Instant Search fails on Outlook 2007 Sub-folders


I sort my messages into folders in outlook and have three sub-folders under Inbox. Whenever I try to use instant search in my sub-folders, outlook displays no results. An instant search on Inbox works perfectly.

Please note that the indexing was complete. I also reinstalled outlook and rebuilt the index from the control panel but search still fails. Also note that this is a re-occurring issue. The search works at times and not at others.

I have attached a screenshot of the failed search. Please take a look and advise.