I use an IPT as a test device and have about 50 test programs on it. My provisioning profile expired and I noticed the programs stopped working. So I figured it was because of the expired profile, as nothing else changed (no updates / upgrades) I reset the provisioning profile and compiled and ran a few programs, everything's fine. Except, the older test programs. They start to load, then freeze up. I have to power down the IPT. I assumed before this was because of the expired profile, but now they still don't work. I tested the same apps in the simulator and they work there. Some of these are the standard Apple API examples (accel graph) So I recreated some of them, and they work when I recompile them. This lead me to thing it's a compatibility issue between API's or something, but NOTHING has been updated or upgraded. This isn't a huge problem, as they are just my test apps, but I'd like to know what's going on here. I had apps compiled and running, then they just stop. No message, nothing. I have to power down the device. Is there some log on the device that I can look at to give a clue what's going on? Isn't the 'Home' button supposed to override the app and force it to close? Mainly I'm concerned about knowing this stuff in depth... Edit: on example is Bubble Level, it runs on the simulator, but when I run in now on my IPT, it loads 1/2 the graphics and then goes stops returns back to the OS, I run it a second time and it locks up and I have to power down the device. Same with the Space Vikings from a book I'm reading... but I recompile it and now it works fine.