I too am having this a very similar issue and have been trying to find a solution for this all day.
I have a late model 17" Macbook Pro running OSX Lion with all updates in place. I use Mail on a daily basis, 12 hours out of every day. I use the Search function at least 15-20 times a day, and up until Yesterday, it worked just fine. I have done no recent updates or changed any settings, but all of a sudden the Search function no longer works properly.
- I can select "subject contains" but am unable to select to search "entire message".
- When I enter a word or phrase to be searched and select the ALL tab to search the enitre Mail database, it is unable to find messages that I know contain the phrase. When I then do the same search within a specific mailbox, it finds the message just fine, but then when selecting back to ALL, it disappears.
This is very annoying, and frustrating that I have been unable to find a solution for this. Any help is greatly appreciated.