"This field name is not known" error when upgrading from VS 2003 to VS 2005

When we upgraded our web servers from VS 2003 to 2005, our crystal reports web viewer began having a problem with reports that contained sub-reports. We now are getting the following error on the web page. The reports were developed in Crystal 10, but I upgraded them to Crystal 11 but still recieved the same error.

Any help would be greatly appreciated.

thank you

This field name is not known. Error in File C:\DOCUME_1\DMDEVB1\ASPNET\LOCALS~1\Temp\CategorybyStateProductDist {B0FCB37B-A7DB-4786-AD69-55568EC94923}.rpt: Error in formula . '{usp_wd_RptCategoryByStateProductDist;1.State} = {?@State} ' This field name is not known.