This was the most painful error I have found. The error occurs when trying to turn out of office assistant off and you get an error that says "command is not available". Following the suggestions in Office Helpfile do not resolve the issue and following microsoft KB Q327353 does not resolve this issue.
Fix as is follows:
- Help -> About -> Disabled Items
- Enable any items that appear in this dialogue by selecting the item and clicking on Enable
- Close
- OK
- Exit from outlook
- Start Outlook and out of office assistant should now be available