Dock icon blank out, as well as whole dock, programs crashing

[onlythecat]

Hi! I have a 24" iMac, and just recently I started have two problems. First, well I was changing screensaver and a few other settings (nothing important), the Control Panel window just disappeared. No This Program Has Crashed or anything. Then my dock stopped increasing size on mouse over as it normally does. (Yes, I checked the setting - they did not change.) I restarted, and for a second or two the dock was white. Then it changed to just one application whited out. Then, when I was in Firefox, Firefox crashed. This time with the Program Crashed window. Well I was trying software update, that to crashed partway through. I tried again, and this time it got through checking for updates (last time it only got 75% or so), and it told me there were not updates available. In fact, Firefox just disappeared again (no window), but it saved what I had typed. (And again.) It seems like this crash is related to clicking "Manage Attachments".