There's no pattern yet for when this happens or what could trigger it. That issue seems to be pretty rare, though. For some it happens during boot, and for others after waking the Mac from sleep.

It is nothing that would or could lead to kernel panics, though.

As far as my own testing is concerned, the issue of AppleIRController.kext not getting loaded for the internal IR Receiver could be reliably fixed by installing the latest version of Candelair.