I used to have the Left Shift Key set as my button to toggle auto-aim on and off but I've realized it no longer does anything (so it use to work at some point) I've unset it but am now unable to set anything to use the Left Shift key.
It still works for chat and outside SK however so I don't think it's anything wrong with my keyboard.
Confirmed. Had auto-aim toggle set to left-shift for ages and am now unable to use it, yet Left-Shift works perfectly in all other locations both in and out of spiral knights.
It works fine for a friend of mine from Sweden, however.