We encounter this error when an night unix executing the stored procedure and the error is catched by exception handling and logged
in the log table .

We try to re-create the envionment and re-execute , and no error.
the testing environment is build up in the same structure and same
data ( on the other words , it is a clone of live environemnt).
the code is reviewed and we didn't find any lines which looks like 'mismatched variable/column length issue' . So I was thinking whether it could be a kind of oracle internal bug ?

our db is oracle9.0.6 on solaris9.