I found the solution for this error here:
http://forums.techguy.org/business-applications/111009-resolved-mpoai9-dll-error.html

Copy and paste of the relevant post:

After talking at lenght with Microsoft, we did the following to correct the mpoai9.dll error:

Saved the current registry.
Opened the registry
Find: mpoai9.dll
Deleted (from the right side) all values with the error.
Worked!

I found the errors under the follwing:
Outlook
Visio
Word
Powerpoint
Excel
Internet Explorer
Publisher