Thanks for you reply.

My code runs on CF 1.0 SP3
Here is the full code of a sample to replicate the problem:

using System;
using System.Drawing;
using System.Collections;
using System.Windows.Forms;
using System.Data;

namespace MemTest
{
/// <summary>
/// Summary description for Form1.
/// </summary>
public class Form1 : System.Windows.Forms.Form
{
 private System.Windows.Forms.Button btnHibernateAll;
 private System.Windows.Forms.Button btnFree;
 private System.Windows.Forms.Button btnCreateChunk;
 private System.Windows.Forms.TextBox tbMemo;
 private System.Windows.Forms.Button button1;
 private System.Windows.Forms.Button button4;
 public ArrayList al=null;

 public Form1()
 {
  //
  // Required for Windows Form Designer support
  //
  InitializeComponent();

  //
  // TODO: Add any constructor code after InitializeComponent call
  //
 }
 /// <summary>
 /// Clean up any resources being used.
 /// </summary>
 protected override void Dispose( bool disposing )
 {
  base.Dispose( disposing );
 }
 #region Windows Form Designer generated code
 /// <summary>
 /// Required method for Designer support - do not modify
 /// the contents of this method with the code editor.
 /// </summary>
 private void InitializeComponent()
 {
  this.btnHibernateAll = new System.Windows.Forms.Button();
  this.btnFree = new System.Windows.Forms.Button();
  this.btnCreateChunk = new System.Windows.Forms.Button();
  this.tbMemo = new System.Windows.Forms.TextBox();
  this.button1 = new System.Windows.Forms.Button();
  this.button4 = new System.Windows.Forms.Button();
  //
  // btnHibernateAll
  //
  this.btnHibernateAll.Location = new System.Drawing.Point(160, 0);
  this.btnHibernateAll.Size = new System.Drawing.Size(80, 32);
  this.btnHibernateAll.Text = "Hibernate";
  this.btnHibernateAll.Click += new
System.EventHandler(this.btnHibernateAll_Click);
  //
  // btnFree
  //
  this.btnFree.Location = new System.Drawing.Point(80, 0);
  this.btnFree.Size = new System.Drawing.Size(80, 32);
  this.btnFree.Text = "Free";
  this.btnFree.Click += new System.EventHandler(this.btnFree_Click);
  //
  // btnCreateChunk
  //
  this.btnCreateChunk.Size = new System.Drawing.Size(80, 32);
  this.btnCreateChunk.Text = "Allocate";
  this.btnCreateChunk.Click += new
System.EventHandler(this.btnCreateChunk_Click);
  //
  // tbMemo
  //
  this.tbMemo.Location = new System.Drawing.Point(0, 32);
  this.tbMemo.Multiline = true;
  this.tbMemo.ScrollBars = System.Windows.Forms.ScrollBars.Both;
  this.tbMemo.Size = new System.Drawing.Size(232, 200);
  this.tbMemo.Text = "";
  //
  // button1
  //
  this.button1.Location = new System.Drawing.Point(0, 264);
  this.button1.Size = new System.Drawing.Size(80, 32);
  this.button1.Text = "Close";
  this.button1.Click += new System.EventHandler(this.button1_Click);
  //
  // button4
  //
  this.button4.Location = new System.Drawing.Point(144, 232);
  this.button4.Size = new System.Drawing.Size(88, 24);
  this.button4.Text = "GC Collect";
  this.button4.Click += new System.EventHandler(this.button4_Click);
  //
  // Form1
  //
  this.ClientSize = new System.Drawing.Size(234, 295);
  this.Controls.Add(this.button4);
  this.Controls.Add(this.button1);
  this.Controls.Add(this.btnHibernateAll);
  this.Controls.Add(this.btnFree);
  this.Controls.Add(this.btnCreateChunk);
  this.Controls.Add(this.tbMemo);
  this.Text = "Memory test";

 }
 #endregion

 /// <summary>
 /// The main entry point for the application.
 /// </summary>

 static void Main()
 {
  Application.Run(new Form1());
 }

 private void btnHibernateAll_Click(object sender, System.EventArgs e) {

  int res=WinAPI.SendMessage(0xffff,0x03FF,0,0);
  tbMemo.Text+="Hibernate sent!"+res.ToString()+"\r\n";
 }

 private void btnCreateChunk_Click(object sender, System.EventArgs e) {
  // System.Collections.ArrayList al=new ArrayList();
  if (al==null)
   al=new ArrayList();
  int Count=10000;
  ItemInfo ii=null;
  Exception eeee=null;

  GC.Collect();
  long before=System.GC.GetTotalMemory(true);
  this.tbMemo.Text+="Start GC Heap
Mem(kb):"+((int)(before/1024)).ToString()+"\r\n";;

  for (int i=0;i<Count;i++) {
   try{
    ii=new ItemInfo((i.ToString()),new string('T',i%17),new
string('1',i%19),new string('9',i%7));
    al.Add(ii);
   }catch(Exception ee){
    eeee=ee;
    break;
   }
  }
  long after=System.GC.GetTotalMemory(true);

  if (eeee!=null)
   this.tbMemo.Text+="Exception: "+eeee.ToString()+"\r\n";

  this.tbMemo.Text+="End CG Heap
Mem(kb):"+((int)(after/1024)).ToString()+"\r\n";

  long ss=System.Runtime.InteropServices.Marshal.SizeOf(ii);
  ii=new ItemInfo("0","0","0","0");

  ss=(after-before)/Count;
 }

 private void btnFree_Click(object sender, System.EventArgs e) {
  if (this.al!=null)
   this.al=null;

  this.tbMemo.Text+="Current GC
Heap:"+GC.GetTotalMemory(false).ToString()+"\r\n";
 }

 private void button1_Click(object sender, System.EventArgs e) {
  Close();
 }

 private void button4_Click(object sender, System.EventArgs e) {
  GC.Collect();
  this.tbMemo.Text+="Current GC
Heap:"+GC.GetTotalMemory(false).ToString()+"\r\n";
 }

}

public class ItemInfo {
 public string TruckNo="";
 public string ID="";
 public string Code128="";
 public DateTime Time;
 public string Name="";
 public static string delimiter=";";

 /// <summary>
 /// 0-áÒÔÉËÕÌßÔ Å ÚÁÒÅÄÅÎ ÏÔ ÂÁÚÁ
 /// 1-áÒÔÉËÕÌßÔ Å ÚÁÒÅÄÅÎ ÏÔ ÕÓÔÒÏÊÓÔ×Ï, ÎÑÍÁ ÇÏ × ÂÁÚÁÔÁ
 /// 2-áÒÔÉËÕÌßÔ Å ÉÚÔÒÉÔ!!!
 /// </summary>
 public int Status=0;

 public ItemInfo(string truckNo, string id, string code128, string name) {
  TruckNo=truckNo;
  ID=id;
  Code128=code128;
  Name=name;
  Time=DateTime.Now;
 }

 /// <summary>
 /// óßÚÄÁ×Á ÄÁÎÉ ÚÁ ÁÒÔÉËÕÌ ÏÔ ÒÅÄ
 /// </summary>
 /// <param name="Row"></param>
 public  ItemInfo(string Row) {
  string str=Row;
  string cell;
  int col=0;
  int endpos=0,startpos=0;

  while(((endpos = str.IndexOf(delimiter,startpos)) >= 0)&& (col<(5+1)) ) {
   cell=str.Substring(startpos,endpos-startpos);
   cell=cell.Trim();
   startpos=endpos+1;
   switch (col) {
    case 0: ID=cell; break;
    case 1: Code128=cell; break;
    case 2: TruckNo=cell; break;
    case 3:
     try {
      Time=DateTime.ParseExact(cell,"dd.MM.yy",System.Globalization.CultureInfo.CurrentCulture);
     }
     catch{}
     break;
   }

   col++;
  }
  //ðÏÓÌÅÄÎÁÔÁ ËÏÌÏÎÁ
  try {
   cell=str.Substring(startpos);
   DateTime
dTime=DateTime.ParseExact(cell,"hh:mm:ss",System.Globalization.CultureInfo.CurrentCulture);
   Time=Time.Add(new TimeSpan(dTime.Hour,dTime.Minute,dTime.Second));

  }
  catch{}

 }
 public override string ToString() {
  if ((Code128!=null)&&(Code128.Length>0))
   return Code128;
  if ((ID!=null)&&(ID.Length>0))
   return ID;
  return ID;
  //return base.ToString ();
 }

 public  string ToStringDB() {
  return
ID+delimiter+Code128+delimiter+TruckNo+delimiter+Time.ToString("dd.MM.yy")+delimiter+Time.ToString("hh:mm:ss");
 }

 //òÁ×ÎÉ ÓÁ ÓÁÍÏ ÁËÏ ÉÍ Å ÒÁ×ÅÎ ËÏÄ128 É
 public override bool Equals(object a) {
  if (  (((ItemInfo) a).Code128.Length>0) &&
   (this.Code128.Length>0)  &&
   (this.Code128==((ItemInfo) a).Code128))
   return true;
  return false;
 }

}

public class WinAPI{

 [System.Runtime.InteropServices.DllImport("coredll.dll")]
 public static extern int SendMessage(int hWnd, uint Msg, uint WParam, uint
LParam ) ;

 [System.Runtime.InteropServices.DllImport("coredll.dll")]
 public static extern int FindWindowW(String lpClassName,String
lpWindowName );

 // public extern static int SendMessage(IntPtr hwnd,uint msg, uint wParam,
uint lParam);
}

}

//----------------------------------------------------------------------------------------------------------

Steps to do:
1.Start the program.(initially I get about 9mb free program memory)
2. Press twice the "Allocate" button.(You will see there are 4MB in the GC
heap)
3. Press "Free"
4. Press GC Collect(You will see there are 0,3MB in the GC heap))
NOW:
5A. Try to start Word or IExplorer.  I get the out of memory box
OR
5B: Press twice the  "Allocate" button. The memory would be allocated inside
the GC heap.

For me this means that GC simply does not release the memory it uses, even
in a OOM situation.

Thanks in advance.

----- Original Message -----
From: "<ctacke/>" <ctacke_AT_OpenNETCF_com>
Newsgroups: microsoft.public.dotnet.framework.compactframework
Sent: Thursday, April 20, 2006 10:01 PM
Subject: Re: GC does not release unused memory to the system in WinCE 4.2