I've seen this posted before in many places, but have yet to find a real fix.
I have a web application on dev server right now, and randomly, hours or
days, it returns the expception posted below.  If I copy the
incHeader.ascx.vb over to the server again, it appears to recompile and works
fine, again, for random period of times.  Even precompiling is no help.  Is
there a fix or workaround so this can some stability?  Any help at all is
appriciated.

Server Error in '/' Application.
Could not load file or assembly 'App_Web_3vljbmrv, Version=0.0.0.0,
Culture=neutral, PublicKeyToken=null' or one of its dependencies. The system
cannot find the file specified.
Description: An unhandled exception occurred during the execution of the
current web request. Please review the stack trace for more information about
the error and where it originated in the code.

Exception Details: System.IO.FileNotFoundException: Could not load file or
assembly 'App_Web_3vljbmrv, Version=0.0.0.0, Culture=neutral,
PublicKeyToken=null' or one of its dependencies. The system cannot find the
file specified.

Source Error:

Line 1:  <%@ Control Language="VB" AutoEventWireup="false"
CodeFile="incHeader.ascx.vb" Inherits="inc_incHeader" %>
Line 2:  <%@ Register Src="~/inc/incLanguageDDL.ascx"
TagName="incLanguageDDL" TagPrefix="uc1" %>
Line 3:  <table width="100%" cellspacing="0" cellpadding="0" border="0">

Source File: F:\Inetpub\wwwroot\fideliscare.org\inc\incHeader.ascx    Line: 1

Assembly Load Trace: The following information can be helpful to determine
why the assembly 'App_Web_3vljbmrv, Version=0.0.0.0, Culture=neutral,
PublicKeyToken=null' could not be loaded.

WRN: Assembly binding logging is turned OFF.
To enable assembly bind failure logging, set the registry value
[HKLM\Software\Microsoft\Fusion!EnableLog] (DWORD) to 1.
Note: There is some performance penalty associated with assembly bind
failure logging.
To turn this feature off, remove the registry value
[HKLM\Software\Microsoft\Fusion!EnableLog].

Stack Trace:

[FileNotFoundException: Could not load file or assembly 'App_Web_3vljbmrv,
Version=0.0.0.0, Culture=neutral, PublicKeyToken=null' or one of its
dependencies. The system cannot find the file specified.]
  ASP.inc_incheader_ascx.__BuildControlTree(inc_incheader_ascx __ctrl) in
F:\Inetpub\wwwroot\fideliscare.org\inc\incHeader.ascx:1
  ASP.inc_incheader_ascx.FrameworkInitialize() in
F:\Inetpub\wwwroot\fideliscare.org\inc\incHeader.ascx.vb:912307
  System.Web.UI.UserControl.InitializeAsUserControlInternal() +31
  System.Web.UI.UserControl.InitializeAsUserControl(Page page) +14
  ASP.en_index_aspx.__BuildControlIncHeader1() in
F:\Inetpub\wwwroot\fideliscare.org\en\index.aspx:7
  ASP.en_index_aspx.__BuildControlContent1(Control __ctrl) in
F:\Inetpub\wwwroot\fideliscare.org\en\index.aspx:6
  System.Web.UI.CompiledTemplateBuilder.InstantiateIn(Control container) +12
  ASP.mainmasterpage_master.__BuildControlcontentHeader() in
F:\Inetpub\wwwroot\fideliscare.org\mainMasterPage.master:16
  ASP.mainmasterpage_master.__BuildControlformMain() in
F:\Inetpub\wwwroot\fideliscare.org\mainMasterPage.master:11
  ASP.mainmasterpage_master.__BuildControlTree(mainmasterpage_master
__ctrl) in F:\Inetpub\wwwroot\fideliscare.org\mainMasterPage.master:1
  ASP.mainmasterpage_master.FrameworkInitialize() in
F:\Inetpub\wwwroot\fideliscare.org\mainMasterPage.master.vb:912306
  System.Web.UI.UserControl.InitializeAsUserControlInternal() +31
  System.Web.UI.MasterPage.CreateMaster(TemplateControl owner, HttpContext
context, VirtualPath masterPageFile, IDictionary contentTemplateCollection)
+1978560
  System.Web.UI.Page.get_Master() +48
  System.Web.UI.Page.ApplyMasterPage() +18
  System.Web.UI.Page.ProcessRequestMain(Boolean
includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +543

Version Information: Microsoft .NET Framework Version:2.0.50727.42; ASP.NET
Version:2.0.50727.42