9. August 2011 10:25
After a lot of searching, I finally found the answer here. It seems that when you are using an SqlDataSource that when a parameter is null, it will cancel a select by default. You need to add the attribute of
CancelSelectOnNullParameter="false". It was very frustrating, as using the SQL Server Profiler, the query wasn't even being issued, and it was a pain to track down.
I'm putting this up here, to hopefully help others with a similar situation in the future.