https://bugs.winehq.org/show_bug.cgi?id=30814
--- Comment #34 from bshalm@broadpark.no --- (In reply to Embryo from comment #33)
This bug is still present in Wine 1.7.44, but it was there in earlier versions as well (1.7.37 iirc). However, it's strange since it doesn't happen all the time, so I can't reproduce exactly the steps, but it's there.
For a reproducer just create a simple Windows program ( http://www.winprog.org/tutorial/simple_window.html ) and print the output of GetKeyboardState every second. If you alt-tab while holding keys, the 0x40 bit (which I believe is something wine internal) should stick. I don't have wine or windows available anymore so I can't help you more than this.