I installed FC7 on an Acer Aspire 1503. I saw the same error and encountered sporadic boot and shutdown errors.
I tried ubuntu but couldn't get the graphics to work. I'm presently typing via FC6 on it's first boot - it has an earlier version of 'nash'. This might be relevant. I didn't see the error but the startup was too fast. I'll know soon.
I booted completly problem free with gentoo linux but didn't know where to take that next!
What I've discovered from searching the web is that there are a lot of posts about error BIOS BUG #81, followed by a differing 8-digit number in square brackets. The number may vary, but it's always BIOS BUG #81.
The platforms, hardware, numbers and efects vary. Do a search yourself and you'll see.
In my case with FC7 when the errors came, pressing a key on the keyboard would move the boot to the next stage; then the boot would pause until I generated another input, and so on. Like wise shutdown, where I almost always had to use the external switch to turn off on-board WiFi to complete the powerdown!
Like I said. Do a search and you'll discover it's a lot more prevalent than you might think.