I'm looking in the Hitchhiker's Guide to SQL Server 200 Reporting Services, p 320
If you look on live in:
C:\Program Files\Microsoft SQL Server\80\Tools\Report Designer\RSReportDesigner.config
....do you see this key:
<
Add Key="CacheDataForPreview" Value="false" />This may help you, though they say on the bottom of the page:
"If you make changes to the .config file above, restart VS.NET 2003. Also, from our testing it appears that preview caching works only for previewing reports inside the Report Designer and not when reports are previewed in the RSReportHost.exe previewer."