Strange Message: Outlook 2010 Add-In Error

One of my customers receives (intermittendly) an error message when opening Outlook 2010 (see screnshot).
raw translation from German: "Fatal error with eset outlook add-in. You should deinstall this plug-in if error message appears more than once, you should check for updates or deactivate.Would you like to deactivate this add-in? Yes / No"
Typically my customers selects no, but the message for sure is ennoying.
System is XP 32, NOD32 5.2.9.12, latest updates.
Any suggestions/ solutions available ?

 

This KB Article may help: ESET Outlook Plugin error when starting Microsoft Outlook

 

Thanks for the link. However we currently can not evaluate the outcome as the PC is currently under maintenance due to disk problems. Maybe this also caused the problem. Will see and reply later if problem persists..........