Locked ignition, steering wheel & shift

[wroot]

I am continuing to have a problem with the ignition locking up on my 2004 Boxster S. When this happens, the ignition key will not turn, the steering wheel locks up and the shift lever will not move out of park. The instrument and courtesy lights do work though when the door is opened.

I used to be able to free up the wheel and unlock the ignition by jerking the wheel from side to side, but last week my wife pulled it into the driveway and stopped to unload groceries. When she went back to pull it into the garage, the key wouldn't turn in the ignition. The steering wheel was locked, as was the gear shift lever. I could not break it free even by violently jerking the wheel side to side. I replaced the ignition switch with the new model Porsche part last year. That seemed to fix the problem up until a few months ago.

Have any of you folks encountered this problem and found a solution?
Thanks much for any insights you can provide.