MPB gets very hot while in sleep mode and won't come back on

Question

I've had this happen to me twice now, and I'm not sure what's causing it. Here's what happens.
I put the MPB into sleep mode, put it in my backpack, and when I open it a couple hours later, the machine is very hot to the touch and the fan is whirring away. On opening the lid, the display will not come back and the only way to fix it is a hard restart.
I checked the battery indicator on the side, and surprisingly, it had 3-4 green dots, so it had plenty of power.
The only common denominator I can come up with is that both times this has happened I had been using Fusion 2.01 during the day, but had closed out of it before putting the computer to sleep.
Any input would be welcome!

Answer 1

OK, we are clearly on the same page. We can now exclude (in all probability -- see below)) the lid coming open.
BocaBoy wrote:
Graham, thanks for the response. Since this happened the first time, I've been very careful about making sure the lid is closed and that the Apple light is out. I have seen the light go out, come back on a few seconds later, then go back out again.
Pulsating. A one-second on/off display of that light?
Yes, I'm referring to VMWare Fusion 2.01. This problem only seems to occur when, during the day, I have been in Fusion running my Boot Camp partition as a VM. I want to stress the fact that I close out of Fusion before I put the computer to sleep. I agree that there is something that Fusion is doing to the display adapter that may be causing this problem. The argument against that is that it isn't consistent. There are times I've used Fusion and successfully put the computer to sleep.
OK, so then if this works sometimes, what is different about these times. When you use the Windows software (or even the Mac software come to that -- there could be a conflict) is there any software that may still be trying to access the internet or other processes (in my earlier reply I mentioned iStumbler -- a network utility -- that caused me some slight annoyance until I realised what was going on).
The only other thing I can think of is that if my car goes over a bump that the lid is bouncing opening slightly, causing it to flick on from sleep mode, then go back into sleep. The fit, however, is tight and secure in my pack, so I'm really skeptical of that explanation.
Agree. Although it should not be excluded 100% until proven. Keep an open mind. I take mine on Bangkok buses and believe me, they bounce. I have never had my MBP come on.
No I haven't done any "maintenance" except being manic about doing a SuperDuper backup once a week along with Time Machine. What do you suggest?
Glad to hear about the TM: I wish more would back up.
I think if this were me (it has been) and I were having to do a forced power off, then my first reaction would be to try a safe boot; and then to boot up again. That at least would deal with any stray temp files and/or processes that were cut short. If this happens too often, I would be looking to stronger utilities, more to be on the safe side than to make repairs.
I would also be looking in the Console: a check of the times between when you sent it off to sleep and the time you found it at work, might show what is waking it up. Also, when you do find it running (and can get in) see which processes are active at that time. If you cannot, then the Console is your only resource, methinks.