Originally Posted by purple

Be prepared to prove you purchased Lion. I think they have a line set up to help with just Lion problems for those who purchased it, even if their other Apple Care has gone out.

They might ask you to re-set PRAM and/or SMC. Which is likely to take less effort on your part than reinstalling OS, which will not work if it is a power management problem.

In truth it sounds like a power management issue.