BW Not Returning Data when web-i report executed

Hi Experts,

We are facing critical issue, when we execute web-i report, IN BW the Query not excuting on Database,

We checked in SM50, when we execute the same report by opening another session from same system then both queries are getting fired on database and getting the results for both sessions, some times both queries are not getting executed.

What our opinion is the SQL query is getting locked in BW beacuse of some reason this is only happening for BO reports only, BW reports are working fine.

Please any have any IDEA regarding this let me know.

Thanks,

G Sampath Kumar