Vista - Outlook 7 search failure

Hi all
Dont know if anyone can help me here - this might not even be a Vista issue... but here goes... Vista home premium...Outlook 7.
The search in outlook calendar (in a PST file) has been working fine for me for months - I use calendar, go to instant search, type a word and it lists all instances in the calendar, going back years - fine.
Now suddenly, for no apparent reason, it only displays instances from the last week or so - even though there are evidently loads of instances in the PST calendar going back ages.
Any ideas what has happened?
If it's an outlook config thing that I have inadvertently changed, then feel free to point out my errors, but I really can't see anything that sets it up to only display recent items, and I didn't change anything deliberately!!
Thanks all
Trev

Hi teejay,
It's probably worth trying MS Office Diagnostics to see it helps.
Start - All Programs - MS Office - MS Office Tools - MS Office Diagnostics.

This link may help. Refer Calendar in the blue as well as the white sections.

Outlook 2007 Known Issues

Post back with results.

Thanks JMH
I looked at the issues list and will try re-indexing.
I dont have a Start - All Programs - MS Office - MS Office Tools - MS Office Diagnostics.
possibly because it's not a full install of office 7 - just word, excel & outlook?
But search did work fine, and now it has stopped....(:={{
Thanks again
Trev

Trev,
That's interesting. I only have Word, Excel, Outlook, One Note & Power Point 2007 - not full Version Office 2007, but the Diagnostics is included.
Is it worth considering a system restore to a date prior to the glitch happening?

Nope, theres def no office tools / diag there...
Well I could try a restore, but somehow it 'feels' like the search is only looking at the last 2 months - the same PST searches fine on my outlook 2003 / windoze XP machine...
Ill have a bit more time tomorrow to try things out
Thanks again
Trev