Snow Leopard or FileVault causing problems with Mail Search?

Ok, I have done a couple of things in the last Month.

1. Enable FileVault
2. Upgrade to Snow Leopard

I have found the Mail Search facility seems to fail to find messages. I have to revert to checking them manually if I can remember the rough date they were created. This then proves that the message I was looking for did indeed exist and should have been found using the keywords I used in the search facility.

It could be coincidence and not related to either 1 or 2 but it was working fine prior to these changes and unfortunately I never noticed the problem in between 1 or 2 to know for sure which if any caused the problem :-(

If anyone has had experience of this before or can shed any light on the subject, I would greatly appreciate it

 

I think my problem was to do with file vault.

It was sometime afterwards that I had reason to turn it off anyway and my searches seem ok again now.