I've had similar problems with my ignition - but only temporary and intermittent. My problem is NOT because of tension on the steering wheel. I can be flat and level, no tension in steering wheel and the ignition won't turn until I keep wiggling the key (not the steering wheel) while attempting to turn it. I'm afraid I'll get stranded some day.

I posted this a few weeks ago and only got the "steering wheel" comments. I've had other cars where you can't turn the key with tension in steering wheel - this is different.

Let us know how the fix goes.