Reporting Services Error

Hi,

i installed the WFE on SSRS, and I activeted the reporting services in CA, but If I use SQL report viewer webpart, I get error (If I click Apply):

An error has occurred during report processing. (rsProcessingAborted)
An attempt has been made to use a data extension 'SHAREPOINTLIST' that is either not registered for this report server or is not supported in this edition of Reporting Services. (rsDataExtensionNotFound)

In event viewer: Report Server (MSSQLSERVER) cannot load the SHAREPOINTLIST extension. EventID: 108.

I don't understand why?

Please help!

Thanks,

Niki