Instant Search in Outlook 2007 not working

For some reason, my instant search in Outlook isn’t working anymore. When I am in any one of my folders, and I search for an item that is clearly inside, it comes up with no results. I have tried this a numerous of times with the same result; nothing.

Windows XP SP3
Office 2007

Both windows and office is fully updated.

Any ideas?

Thanks for the help in these forums!