An error has occurred during report processing. (rsProcessingAborted).. Query execution failed for data set

Hi All,

I'm facing a strange problem..
I've developed few reports. they are working fine in develop environment. after successfull testing they were published on web.
in web version, all reports are executing for first time.. if I change any of parameters values or without chaning also..
if I press "View Report"  following error occurs..

• An error has occurred during report processing. (rsProcessingAborted)
  • Query execution failed for data set 'dsMLGDB2Odbc'. (rsErrorExecutingCommand)
    • For more information about this error navigate to the report server on the local server machine, or enable remote errors
    
    

please suggest any alternative ways to overcome this issue
thanks in adv.