Got a new HD 7850 and the first thig I noticed was the Tire/Heat mode can be a bit funky (see screenshot), I know this area is'nt working as intended just yet but I never noticed this particular Bug with my 9600GT. Never consistent either.
Got this in Monaco 1960's driving a Spark last night. Had it a while back in build 69 also but it does not appear too often, I use a Nvidia GFX550ti graphic card running XP pro and build 85.