Hazardous execution oracle request

[Olive]

Hi
I just had a problem of execution may request. They work in a haphazard way. Sometimes it works, sometimes not.
Running a query (SELECT) crash the first call for SqlPrepareAndExecute, and succeeded in the second (one behind the other)
The connection is a native Oracle connection (sqlnet)
If I connect with OLEDB, I have no problem
The concern is that the application uses a lot of stored procedures, I can not afford to convert all these calls anonymous blocks, so OLEDB is not possible in this case.

my setup is as follows:
post seven
TD 5.2 ptf5
oracle 10 (32-bit)
we just migrate desktops, workstations were in XP, and the problem never happened before
what can I do ?
best regards
Olivier