Will upgrading void AppleCare?

Moorgan Hart wrote:
Also, macsales uses OWC ram which is different from the brand Apple uses, which would be the same as buying any other non-apple ram from any other online store. The consequences of which have already been addressed. And macsales is also sight unseen, as is the case when purchasing almost everything off the internet.

You're being unfair in making OWC equivalent to eBay "sight unseen." OWC has three things your eBay seller does not: A long and solid reputation among Mac users, a lifetime warranty, and advance exchange. That last point means that you can have them send you replacement RAM before they receive the RAM you are returning. Besides, "seeing" the RAM (e.g., in your local computer store) isn't going to help you discern that it is of any better quality than what OWC sells "sight unseen." Be a little more fair in your comparisons. With OWC, you have a reasonable expectation that the RAM will be good quality, and if you get a bad one, you have a more than reasonable expectation that the lifetime warranty will be honored and that return/exchange service will be quick and prompt. I doubt you'll get that far with many eBay sellers.

Ignore at your own peril. I've dealt with AppleCare and with genius bar people, and have been given the runaround when I had my own installed hard drive and RAM. And yes, while OWC/Macsales is not Apple RAM, they do consult with Apple on a regular basis to make sure their specs are exact. They aren't the only ones. Crucial is another such company. Otherwise they wouldn't on their own website go to the extra step to ensure you know your vintage of Mac and Mac model number fits the RAM they are selling. Many vendors will only tell you the spec regarding timing, but not say that it fits an early 2008 MacBook Pro. I've been writing accepted tips for longer than I can remember:

http://discussions.apple.com/forum.jspa?forumID=599

And have done the research as much as any individual user can short of actually being with Apple directly. Knowing the problems of kernel panics with bad RAM, and knowing that RAM tests can't detect all bad RAM, means your chances are better if you have a known good product, than an unknown.