Craig

Blocking shouldn't cause your reports to show the wrong (or no) data... unless there is a timeout on whatever application runs the reports. If that's the case, you might want to increase the timeout period. To investigate blocking, sp_who2 is a good place to start. If that doesn't give you enough information, you can go deeper into the internals with DMVs such as sys.dm_os_waiting_tasks. Adam Machanic's sp_who_is_active is also worth looking at.

John