[Zope] Connection Problem with Oracle

[mirette Marzouk]

I created a connection to an Oracle database. Frequently, the connection
breaks and I got a database error in the page that displays the query
result. When I logon as a manager I find that the connection is closed
(by itself, nothing changed in Oracle or Zope), when I try to open it I
get an error "Invalid connection string". Even if I create another
connection it can't work.. After a while it works. Even after restarting
the Zope server the problem persists.

Thanks
Mirette