Hi,
Can you tell us what the Error shows when it runs stand-alone on server ?
perhaps Security problem to access mdb or DLLs,
Do your application needs to create a temp file or access to somewhere in System ?

My guess:

Windows Server uses much better security modeling than Winows XP does. You really should develop on Windows Vista with UAC turned on (make sure you never trip the UAC dialog with your code!). Most likely you need to fix the NTFS permissions your files have so that they can run correctly.

OR

You're running the server application as a service, in which case you either forgot or didn't realize that the System.Environment variables cannot be trusted when running as a service because services are by the OS and not a user. This means you cannot access files with a root anchored path and you have to make sure all security setting are set so that Local Service has access.