failed to open rowset error in sqlserver2000

i am using crystal report 8.5.i tried to call the stored procedure using sql query analyser then there is data returned..
also i tried using crystal report to preview the report and there is also data returned.
however when i upload my project to the server.. i tried to call the webform to open the crystal report. it returns me "Failed to open rowset error".

previously when we are using sybase there is no error. however we migrate to sql server 2000 then there is this error. I have checked the stored procedures and the aspx.vb code already there should not be an error.

Does any know to to resolve this??

urgent~~

Zach