for some reason my bt keyboard which came standard with my 21.5 imac is doing very strange and weird things. at the log in screen when i go to enter my name it just keeps typing a number continously or random letters. i managed to log in using a usb keyboard and then reconnected the BT keyboard and it caused even weirder things. a random button would open apps, touching the bightness button would change volume and brightness together and it just made the computer feel like it was being controlled by someone else. i changed batteries, rebooted but nothing. ill try a pram reset but i doubt that will work. any clues?