I have similar problem also. I checked for tble_Requests table.
This statement didnt return 208 error. There are 131 rows also.
Blocking and Wait Statistics , Bottleneck Analysis and SQL Server 2005 Perf Stats reports return "Database doesn't have the necessary data to run this report" error.
I can only get results for two reports : ReadTrace_Main and Realtime - Server Status.
My SQL server collation is CI_AS
What should I do to handle this problem ?