I got Lion 2 days after it was released, a couple days later I logged into YouTube with my Google account, as I had logged out to log into another account. This was the first time I had logged into YouTube using this account since I got Lion, as I was logged in previously and it kept me logged in, Safari was nice and offered to set up that account for Mail, Contacts, and Calendars so, even though I already had the account set up for Mail, I clicked on "Setup", "Ok", or whatever it is that it said, and it set it up for me, this was all fine.
I then went into Settings and cliked on the new "Mail, Contacts, and Calendars" button that was added in Lion, I noticed that it had the account set up, but then set up again for iChat, there were to accounts set up, one had iChat, the other had everything else.
So, I deactivated the one with just iChat, and activated iChat for the other one, well... it didn't like that, I check the box and it immediately unchecks, repeatedly.
I eventually just remove both accounts and setup the account anually for everything. That goes well, and everything goes fine.
Then, the next morning, I notice that I have 5 unread emails, on my iPhone 4 and my Mac. I open Mail on my Mac to read them, and I see no unread emails. The badge is still there, and the Inbox button has a "(5)" next to it, and when I open the menu to see all the mailboxes, it has a "5" next to my inbox there as well, but there are no messages displaying as unread.
I decide to go to gmail.com and view my inbox there. (Now that I think about it, I think that my iPhone didn't show as having any unread emails.) I see that there are 5 unread emails, I read them and hope that will fix the problem.
I'm here asking about it, so it didn't...
There are still 5 unread emails, I tryed restarting Mail, that didn't help, I've even restarted my computer a few times since then, I tryed removing the Gmail account, at which point the "5" goes away, but it comes back when I re-add the account.
The number does go up to 6, 7, 8, etc. when more emails come in, but it never goes below 5, I can have 1 email and it will display a "6".
Thanks for reading the lengthy post, I like to provide as much detail as possible.