Report Works In Preview Mode But Not In SSMS 2005

Hi,

I've created an SSRS report in Visual Studio 2005 which runs fine in the preview. I have a list of server names which when clicked on expands to a list of databases on the chosen server. When I click on a database it then queries a table of information and displays information on that database. The query is something like:

SELECT * FROM MyDB.dbo.DB_info
WHERE ServerName = @ServerName and DBname = @DBname


This works fine in preview mode. When I run it in SQL Management Studio via the Custom Reports menu it only works when the chosen server is the one that contains MyDB. I've run a trace and can see the query being issued when I use preview mode. However, when I run it from SSMS I don't see any query being issued to the database. This seems strange as it does return data in the instance described above and if I put MyDB into single-user mode it then complains that it can't access it so it is obviously trying to communicate with the database but not showing up on the trace. I've selected all events and only put a filter on the database name.

Seeing as all of the information is in the same table it seems odd that they query only works when the server name is the one where the database is held and that the query is not shown up in a trace. I'm running the report under the same credentials too.

I'm completely baffled by this so I'd be very grateful if someone could explain what might be happening here.

Thanks.