I've found the cause of the problem, and I'm working on a fix. It's not that easy to fix, as the problem is that at the start of a race weekend the team power values are calculated. These are stored in a save game and used again when you reload the game and start a new session later in the weekend. This is all fine, but with the new car specific power feature, the power values are now located in GPxPatch and not stored in the save game. So when you reload the game, all power values are still zero. The fact that the cars still do something is caused by the fact that the values contain a small randomization. So some cars move forward, some backward, and some keep standing still.
I'll have to make sure the car specific values are stored in the save game. But your existing game won't be working anymore, as it already has the power values set to zero inside the save game file. I hope you haven't overwritten your game during a season, or you'll be out of luck until the next GP weekend. Otherwise I'll have to prepare some custom fix to restore power values when they are zero.
René Smit, Independent Software Developer.
Download my GPx tools
here.