Lion Mail missing folders

After upgrading to Lion, Mail was missing some folders and some folders were missing messages. I tried Mailbox, Rebuild and it brought the messages in the folders that were there, but some folders were just not there. I recreated my Exchange account/mailbox and it was good for a day or so and then this morning, one of my highly used folders was gone and earlier today, a folder I have called "`Apple" of all things (the grave accent in front is to sort it near the top, but now that I think about it, the other folder that disappeared had a grave accent in front of it too - though this was never a problem with Mail before Lion) disappeared and I tried deleting the indexes and that didn't bring it back. I had to delete and create the account again.

It seems like there is a bug somewhere in Lion Mail. I may try removing the grave accents to see if that helps, but then what do you all use to keep some folders handy near the top? Exclamations or 1-, 2-, etc?