I have an iMac from mid-2006. Lately random triangles have appeared on my display, they look like this: http://imgur.com/lmj7D (It's a little hard to tell because the portion being distorted is white on white). My iMac: Mac OS X Version 10.6.8 2 GHz Core Duo 1 GB RAM ATI Radeon X1600 I have no idea what might be causing these problems or how to fix them. The only thing that I've had changed on my computer since I bought it was having the harddrive replaced when my original one kicked the bucket on me. Any one have any info on what might be wrong or how to determine what the problem may be? (While I am technically inclined, it's been a long time since I've ever done anything with computers, so I may need a little help if anything requires some direction) Thanks for any help.