Problems whith PL/SQL and statistic

I'm a newbie with Oracle.
I've an application bases on PL/SQL and C (on Alpha/OSF). This application runs fine.
When I decided to run statistic with
ANALYZE TABLE prova COMPUTE STATISTIC... I get:
Table analyzed.
Therefore app. doesn't work anymore and I get a lot of core dump. If I drop statistic, everything works fine again.

Anyone have any ideas about this problem.

        Cheers
        Gabriele