Hey Phil,

Thanks for the advice - you definitely started me off on the right track. It was indeed an issue with the 32 bit vs 64 bit environment, but what threw me off was the fact that changing the package configuration didn't solve the problem.

The reason is because, even if the package is configured to use the 32-bit environment, it doesn't actually do that if you run it with dtexec!.

When running dtexec, by default SQL Server uses the 64-bit version!

So the trick is to force SQL Server to run the 32-bit version of dtexec, then all the problems are solved!

See this thread for more information:

http://www.sqlservercentral.com/Forums/Topic617157-148-1.aspx