Well, there's been a revelation. I happened to visit my parent's house this afternoon and was about to show the problem to my mom so I opened up the lid (this is all after swapping the memory even though that didn't help) and turned on the computer. The screen was the normal gray, but still had some jittering issues and grain problems, but the apple logo wasn't green. That was odd. So I opened the screen up just a little wider and then bingo! The problem totally went away.
So it looks like there's some issue going on with the connection between the LCD panel and the internals of the computer. I don't know if it's bad, loose or what, but it isn't right. This would explain why the issue started happening when opening the lid after the computer was in sleep mode. The weird part is that I baby the computer and it's never mishandled. On top of that, it's not my main computer so it usually only gets used once a day during the week for light computer usage in the evenings (some days not at all) and more often on weekends when vegging on the couch. My point is that screen doesn't go through the open/close process much at all.
Don't suppose that'll be something they could do an in-store exchange for? I bought it online from MacConnection.com on 6/9/09 and received in the mail about a week later. I just checked genius bar appts for tomorrow and I won't be able to make their times. Oh well, they wouldn't fix it there anyway. I think I'll call apple support first thing on Monday and demand a new unit right away and have it shipped to me (or arrange to pick it up at the apple store) with a temporary charge on my credit card that they'll remove when the get the other unit back. I really don't think it's fair to wait another two weeks like I did for them to fix a stupid key on the keyboard!
