Hello Pieter,

   I didnt got the chance to work with COM-.net interopratbility in a
professional env...But i had spent lil bit of my time with this for the sake
of learning. I think the only thing that we have to make sure is that. the
assemblies and the corresponding type libraries generated from these
assemblies are residing in the same folder, Suppose your assembly is having
a class that contains a method that returns or accepts a type (say a class
residing in another .net assembly), you should create the tlbs for those
types as well, and it should be present at the same folder where these
assemblies are residing.

   Nothing esle i can remember at thsi time..

regards
Sujith S.Varier

To make .NET assemblies available to applications that use
COM you need to use this:

NET Framework Tools Assembly Registration Tool (Regasm.exe)
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cptools/html/cp
grfassemblyregistrationtoolregasmexe.asp

.NET Framework Developer's Guide  Registering Assemblies
with COM
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpguide/html/cp
conregisteringassemblieswithcom.asp

see also
.NET Framework Tools Type Library Exporter (Tlbexp.exe)
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cptools/html/cp
grfTypeLibraryExporterTlbExpexe.asp

You may also have to add some code/attributes to the .NET
code to supply additional COM metadata/functionality.

To have a .NET application access a COM component you create
a Runtime Callable Wrapper (RCW). Visual Studio can do it
for you. However this is the tool to create one
independently:
.NET Framework Tools  Type Library Importer (Tlbimp.exe)
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cptools/html/cp
grftypelibraryimportertlbimpexe.asp

For ActiveX components see
NET Framework Tools Windows Forms ActiveX Control Importer
(Aximp.exe)
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cptools/html/cp
grfWindowsFormsActiveXControlImporterAximpexe.asp

Use Visual Studio .NET only to create the RCW if your
project is the only one that uses that COM library.

If the COM component is used by multiple .NET projects and
was developed in house create a Primary Interop Assembly
(PIA) and include it in a setup merge module.

.NET Framework Developer's Guide  Primary Interop Assemblies
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpguide/html/cp
conprimaryinteropassemblies.asp

.NET Framework Developer's Guide Registering Primary Interop
Assemblies
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpguide/html/cp
conregisteringprimaryinteropassemblies.asp

if the COM library was developed by a vendor, obtain the PIA
from them.

In General

C# Programmer's Reference   COM Interop Tutorials
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/csref/html/vcor
iCOMInteropTutorial.asp

Visual Basic Language Concepts  Introduction to COM Interop
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/csref/html/vcor
iCOMInteropTutorial.asp

Microsoft .NET/COM Migration and Interoperability
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnbda/html/comi
nterop.asp

.NET Framework Developer's Guide Building .NET Framework
Components for Interoperation
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpguide/html/cp
conBuildingNETFrameworkComponentsForInteroperation.asp