Bad ignition lock cylinder, or?

Hello
This is about my '99 Taurus, 54K.
Today I couldn't put the car in gear. It starts normally, but the gear shift is stuck in P position.
Only way to get movin' is to turn the key half way. Then adjust the gear shift slightly towards R, maybe 1/3 way towards R. Then start the car, and then choose gear. It now works fine, but as soon as I put it in P, it's stuck again.
Question is whether this might be a faulty lock cylinder or what? Is it easy to fix, or do I have to hand it over to the dealership for a costly treatment?
Any help will be greatly appreciated.

Thanks
rodgerma

One possibility is a bad brake light switch or a wire going to it. Have someone look for brake lights while you push the pedal.

Hello again
Right on bustedratchet.
Some more research resultet in this clue:
"There is a solenoid in the shifter mechanism which prevents the shifter from being moved out of park until it is energized. The brake pedal switch closes when the pedal is depressed energizing the solenoid..."

Well, I didn't think it was relevant, but the problem occured when I had the car in for an oil change at Wal Mart. Not only did they take 3 - three - hours to do it, but they also gave me the breaking news about a possible faulty transmission which was a little later dismissed with "You should take the car to the dealer and let them take a look at it."

I must admit I don't usually crawl around on the floor of my car, but the brakelight test came out negative, so a closer look was necessary.
It turned out the brake pedal switch has two connectors, but only one was connected properly. The other one was bent outside the connecting plug. Obviously someone at Wal Mart had messed up with it and not done a too good job putting it back. Needless to say, I wasn't too pleased with my Wal Mart experience today. But who would have thought they would mess up a car by just a mere oil change?
Anyways, the fix was cheap, and I found this a very useful forum;-)

Thanks again and take care
rodgerma