GT5 bug?

[Rumpy]

I've started to notice something weird going on tonight while playing with 2.06. I've been playing one of those seasonal challenges, and the performance points on the car have been going up by themselves. I'll be doing a race, and then the performance points have gone up by 1,  which can be frustrating when dealing with challenges that require not more than max amount allowed, so then I go to adjust the power, take it a few notches down, do a race and then come back and it's gone up again. I have to keep doing this just to be able to race in the challenge.  I haven't upgraded my car at all other than giving it an ICU upgrade. What in the world is going on?

If anyone wants to test this, it's the FF 430PP challenge. It's currently the newest one.