Your symptoms sound a lot like how my computer was behaving before the hard drive died. Has your computer been slowing down as well? Are you starting to hear a strange sound coming from your computer? Maybe these symptoms haven't shown up yet--I know the burning problem came first and the other symptoms took a while to show up in my case.

I'm going to recommend running the hard drive checking utilities that go with your hard drive. If you get a SMART status error, contact the manufacturer immediately, because that's sufficient ground for an RMA in most cases. When we tried to run the hard drive checking utility on my dying hard drive, it wouldn't even run because SMART status on my drive failed (the most severe kind of SMART error). We told Gateway about it, and they shipped me a replacement immediately (well, if you can consider a refurbished Hitachi a true replacement for a Western Digital).