When I start up Burning Crusade by running the .app directly (not via Battle.net), I get the game login screen. If I start entering my password then press Cmd-A to select it (e.g. if I’ve mistyped and want to start over) then instead of selecting the text, it deletes all but the first character. This seems to be a new issue as I’m pretty sure it didn’t happen before the pre-patch.
The email address field is fine; only the password field seems to be affected.