Do you have Oracle Metalink support access? If so, lookup support Note: 415637.1. If you are running Oracle 10.2.0.3 then this Note identifies an Oracle bug that matches the behavior you reported exactly with the second execute aborting. If you don't have Metalink access, try setting your Oracle db parameter CURSOR_SHARING=EXACT (the workaround mentioned in the support note). The note also implies there is a bugfix for this issue. Get your DBA involved.