Gmail on your Android phone shows there are 5 unread messages in your inbox:
But looking at the message list, no matter how many times you refresh, you still only see 1 or 0 unread messages. Meanwhile, messages you deleted from Android Gmail may show up again as unread on desktop email. This is not a big deal, but annoying.
So simple, I felt dumb for not thinking of it sooner.
- Disable the sync feature of the phone (Settings -> Accounts and sync)
- Go to where you can "Manage" the Gmail app (for me, it's Settings -> Applications -> Manage applications) *NOT* the settings inside the Gmail app
- Press the "Clear Data" button.
- Re-enable sync.