iHandy and Clinometer remember your calibration settings, so unless you reset them before you did the iOS update they would now give you incorrect readings.
Try deleting the app and doing a fresh install.
My racing games are now fine and Camera+ which shows you a horizon is fine as well.
okie dokie. i am on it right now.
I just did a fresh install of Clinometer and iHandy and both are fine for me. I really do think that the iOS update has fixed this problem.