Problems catching Overflow 1426 jdbc

Hi,

during an simple INSERT into table in a stored function,
a ORA 1426 is raised. Thats OK, I already identified the
column that is exceeded.
I am surprised about the fact, that if I trigger my
stored function from sqlplus, my pl/sql routine catches
the exception and returns properly. The same trigger from
out an java-application via jdbc, seems not to catch
the overflow, does not end and I retrieve sqlexception
because of closed connection later on.

Snippet from pl/sql:

[...]
EXCEPTION
WHEN OTHERS THEN
BEGIN
ROLLBACK;
SP_LogError('SF_DO_SOMETHING ['||depotID_i||']',SQLERRM, SQLCODE);
commit;
RETURN FAILED;
END;
END SF_DO_SOMETHING;

Oracle: 10.1.0.5.0
Java: java version "1.5.0_12"

Thanks for hints in advance!

CARSTEN