Custom Toolbar Still Disappears (Renamed .dat file, checked for Outlook running in background)

Hello All,

I have a COM addin for Outlook and on some machines, the custom toolbar &
menu item seems to disappear from time to time.

I have renamed the .dat file and also checked for a hidden instance of
Outlook running in the background but the behavior continues.

The toolbars are created as "Temporary" which, in theory, should not affect
the toolbars during the actual session.

Any ideas?

Regards,

TC