Comment 8 for bug 804321

Yes, definitely seems to deal with IOKit.

Here's the kernel.log entries during the race condition:

kernel[0]: /SourceCache/xnu/xnu-1699.22.73/iokit/Kernel/IOUserClient.cpp: mach_msg_send_from_kernel_proper {1000000d}

This message is repeated in an infinite loop until either InsomniaT is switched back to the 'On' setting, or you unplug from a power source.