I have been paying attention since you started the thread - all the adds I get on CC are Kaplan, student loans - that sort of thing. I do have a pop up blocker though. And I use firefox which seems to let in fewer nasties.
Oh just noticed your post#8 and you have firefox also. Have you tried clearing your cookies and temp internet files as EmeralK suggests in case something is lurking there? I have not seen anything other than college related adds.