Are you using ADO or ODBC to access the data? If not, then MDAC wont affect it.

>I got often a weird error message when trying to do a REPLACE (or INSERT or any table update command) on any table opened in SHARED mode and without NOUPDATE clause at all. I don't understand why this kind of error occurs because we have no table opened in read-only mode. It can happen anywhere (on any table) and anytime. I found that a simple reboot seems to fix that. Do you think it could be related to MDAC (Microsoft Data Access Component) ? Because I have already read something about that on a forum