[glvee]

I bought my 1999 Alero used, with this same problem. In my case (I don't know if this will work for you) I just have to find the "sweet spot" by slowly inserting the key 95% of the way in, then very slowly (millimeter by millimeter) and trying to turn it as it goes in the rest of the way; if it goes all the way in without turning, I slowly (again, millimeter by millimeter) pull it out, while continually applying pressure to find the right spot where the key will turn and start the car. Hope this works for you.