I'm working on a Sql Server Reporting Services solution that queries across both a Sql Server data source and an Oracle 10g data source. My dev box is Windows 7 64bit with Sql Server 2008R2 and I'm hosting IIS7 and SSRS on that system for development; using VS.NET for designing the reports.

I have been having errors when running the report where SSRS complains about loading the 32 bit Oracle client in a 64bit process. There a number of threads out there about how to solve that. The thing is, they all come down to making sure you have the 64bit Oracle, client which I do. The weird chain of events I have goes like this:

• Create initial Oracle datasource and wire up report (it works)
• Edit Oracle datasource connection (it stops working with BadImageFormatException 32bit/64bit error message)
• uninstall and reinstall Oracle client (it works)
• Edit Oracle connection again (it stops working with BadImageFormatException 32bit/64bit error message)

So short of reinstalling the client every time I change the connection string I am at a complete loss. Has anybody seen this sort of behavior? And if so what the heck am I doing wrong?