Error message says Outlook does not close properly

[sabob]

Almost every time I open Outlook 2007, I get the message "A data file did not
close properly the last time it was used and is being checked for problems.
Performance may be affected while this check is taking place."

What is going wrong, and how can I fix the problem? The check is always
satisfactory, but it's annoying to see this time after time.

 

[Roady [MVP]]

Do you close Outlook before shutting down your computer?
When you close Outlook verify that the outlook.exe process also actually
quits. If not, usually addins are to blame.

 

[AusMossy]

I was having the same problem, though only after I moved to Vista. I found
that if you don't close Outlook before shutting down your PC, but let the
shutdown take care of it instead, you don't get the error next time you start
Outlook.

Strange but true.

 

[tooleybucc]

Almost every time I open Outlook 2007, I get the message "A data file did not
close properly the last time it was used and is being checked for problems.
Performance may be affected while this check is taking place."

What is going wrong, and how can I fix the problem? The check is always
satisfactory, but it's annoying to see this time after time.