Heat/fan problem after hibernate

Hello

I've got a 2011 model MacBook Air 13" with the stock i5 1.7GHz CPU. It's been an absolutely fantastic machine but I do have one little niggle that no amount of PRAM or SMC resetting seems to fix. I've narrowed it down to something I can reproduce quite easily.

After closing the lid and allowing the laptop to sleep, removing mains power before or after sleep begins, after about an hour it goes into hibernation, which is expected. Now, if I wake the machine after this point without plugging in the power cable, everything is fine. I can then plug the power back in once it's awake with no problem. However, if I put it back on to mains power before waking it, then proceed to wake it, within a few minutes the laptop gets very hot, and only the smallest of workloads kicks the fan into life, never to be switched down again. I can fix this by simply putting the laptop back to sleep and immediately re-waking it.

I can only assume this is some kind of bug in the CPU performance controls, maybe clocking it at a fix higher speed on the first wake? It's been with it through every version of Lion, and through recent EFI firmware updates.

It'd be great to know if it's just me, or if others have noticed it too. It's not a big problem, it's just a little annoying!

Thanks

Steve