Reinstalling the game should fix it, and I believe there's a starforce reinstaller on their site somewhere which should also do the job.
Just a small rant, I hate starforce more than I thought possible to hate a peice of software, it has the unique ability to make me want to break stuff in just a few seconds. When I spend my money on a game I want it to WORK, not go through some b**lshit copyprotection that half the time doesn't work right. E.g. Trackmania, great game - one of my favourites, I purchased a legal copy, and yet I use a pirate copy. Why? None of that starforce rubbish. It really screws around that much sometimes.
Anyway back on topic, I'd hold out for NetKar Pro definately, it looks worth the wait, I've still not purchased rFactor because I only race online, and it doesn't seem like a good platform for that.