Crystal With MSDE..>HELP!

I get "Unable to Open Database" when I try to run Crystal Reports with MSDE. Any ideas.
The reports work fine with SQL Server and MS Access.
Thanks in Advance.I'd need more information before I can offer advice.

How is security set up? Integrated, SQL Server?

Using OLEDB or ODBC?

What version of Crystal? MSDE? Are both on the same computer or is access across a network?

etc...|||Thanks for your reply,

I am using MSDE 1.0(SQL Server 7.0) and Crystal Reports Version 8.5. The application that runs the reports is on the same machine as the database for now. I am using ADO (MDAC 2.7) to connect to the database.

The reports are made off a MS Access Database (2000) and I change the driver at run time, as it checks for the database type that the application is running off of. I am using:

Crpe.Tables.ConvertDriver(pssql.dll)

function to convert the driver from Access to SQL Server.

Once I try to run the reports it gives me Crystal Report
[error 533:Unable to Open Database]

But once I run the same reports on MS SQL Server or MS Access Database it works fine or even once I run these reports off of MSDE running on XP Professional it still works fine.

This has become a real chanllenge. Any help would be appreciated.

THANKS IN ADVENCE. :)