I also have the same problem when using Mobmeter. I found that if I want to check the temp, I have to pick the proper time to do so (i.e. when there is no drive activity, or drive activity has just completed). I only bring it up for a moment to check it, then back out of it. When the lock up happens, the drive activity light comes on solid, and I can do nothing to bring the unit out of this state, so I have to power it off/on. Does anyone know of any other temp software out there that works properly??