Picking up http://www.keil.com/forum/59213/
With tracing issues on M3/M4 parts pay VERY close attention to the speed you tell Keil the chip is running (Core Clock), and what you're actually running the part at.
I wish this forum would read-only threads before some lost soul posts to them, not afterward. Oh look someone revived an old thread, lets close it now. Not sure of the logic here, someone should decide upon some behaviour that makes sense, ie make it read-only after timeout so you can't post against it, or start the timeout over if someone posts against it.