My in-laws have a 2011 21.5 inch i5 in the basic configuration that they're having problems with. They essentially get the beach ball that freezes when they access programs....especially safari. They have to restart and run a recovery disk check (disk utility according to them) every time. It's very frustrating and they've had AppleCare "fix it" three times in five months. First was reported as a software issue. Genius reinstalled OSX with no resolution. Second time resulted in a hard drive replacement that didn't seem to help. They just picked it up today with what the genius said was a software fix(new os install) and it's still freezing. It takes a little bit, but still freezes after a few hours. What do you guys think the issue might be?. I have not looked at the computer, so these are my elderly in-laws describing this to me. They are getting frustrated with AppleCare because they don't seem to know either. Any advice you can give would be appreciated. Thanks.