weird visuals

Well I literally haven't posted here in forever because none of it seems that important anymore, but I kind of need you now. I've had two problems when I try to use finder. It is visually screwing crap up. And this is repeatedly happening, so while closing finder window temporarily fixes the problem, it just keeps on reappearing all over finder.

Secondly I only have 512MB ram so I expected I'd need to eventually upgrade. I bought this in June and it was great. In the past month however it experiences time when it is so slow, like slower than my 12 year old windows laptop. but other times it's great and is zooming like the day I got it. And the thing is 95% of the time the only things I'm running are firefox, msn messenger, aim, itunes and maybe textedit, and I don't think this should cause the extreme beachballing it does.

It also had it's 4th kernel panic today *sigh* Anyone who knows my story knows I haven't had the smoothest transition to macs.

Oh and here's a pic of the graphic problem and of a graphics problem in itunes (stop laughing at me for having nysnc!)

 

please please please help me