Help! T40p always reboots after going into sleep.

[atanasoff]

Pardon the note of despair, but I've gotten nowhere figuring this out.
Machine: T40p XPpro SP2 2GB all standard hardware.
The issue: If the machine is put into sleep mode either by Fn-F4, by timer when on battery or by the lid switch it reboots, thus trashing whatever work I had been doing. The reboot occurs when it is brought out of sleep. It is repeatable and occurs every time. Everything else works normally and I am at a loss for where to start - the only dividing line between when the system worked normally and was an electrical storm. Lightnening hit within a hundred yards while the system was hibernated but there was no damage to anything in the house including other computers (an elevated rail line runs nearby, maybe that grounded out the lightning).

There's nothing in the System, Security or Application logs - all is OK there. Google shows this to be a common issue with Vista, but I saw nothing exactly the same with XP.
Is there a registry entry involved or can I install software which tracks what happens when the system goes into/out of sleep?
This is my only computer and I can't ignore the issue.

[GomJabbar]

You can change how Windows responds to a stop error. Change the action on the last thing in the list below. This should help you diagnose the problem if it is a stop error causing it.

1. Open System in Control Panel.
2. On the Advanced tab, under Startup and Recovery, click Settings.
3. Under System Failure, select the check boxes that correspond to the actions you want Windows to perform if a Stop error occurs:

* Write an event to the system log specifies that event information will be recorded in the system log.

* Send an administrative alert specifies that your system administrator will be notified.

* Automatically reboot specifies that Windows will automatically restart your computer.

[atanasoff]

Thanks. AFAIK I'm not getting a stop error - I get no blue screen, nor any errors in the system log. The issue happens when the machine goes into sleep/standby by normal means, such as closing the lid or the timer when on battery.