doubled characters on keyboard input with external usb keyboard

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Used to work before I updated to android 4.2.2, with external usb wired keyboard.
galaxy tab 2 10.1

when I type characters in the minibuffer or in a buffer, they are inserted twice. In the minibuffer, if I type a letter inthe minibuffer inlower case, it appears as a pair of lth same letter, both upper and lower case.
when I use the delete key, it is aleo sent twice.

Toss me a clue and I'll try to fix it myself!