Error using the Library on a Windows Server 2008 SP2 64-bit

I developed an application (C# Framework 4) using the fdf toolkit running on a 32 bit server and everything works well.

I have migrated this application to a Windows Server 2008 SP2 64 Bits and sometimes this application gives me this error:

System.Runtime.InteropServices.COMException (0x800703FA): Retrieving the COM class factory for component with CLSID {CB830891-2E18-11D1-B8CF-00A0C9259304} failed due to the following error: 800703fa Illegal operation attempted on a registry key that has been marked for deletion.

After this error, I recycle the website pool and the application runs well again.

Details of the application:

1. Registered the libraries FDF.dll, FDFACX.dll and FDFTK.dll in c:\windows\SysWOW64.
2. Enabled in the web site pool the property 'Enable 32-Bit Applications'
3. Enabled 'Do not forcefully unload the user registry at user logoff ' property in the Group Policy Editor

Could you help me?

Thanks¡¡¡

What is the target platform you are building your application for? It will be either x86, x64, Itanium, or most likely "Any CPU".

You can try setting it to x86, that way you know everything is built to use the 32-bit version of .Net. Alternatively you can run CorFlags on your assembly(ies) to change it to x86 without recompiling.

If that doesn't solve the problem then we will need more code :)