What's up with the pop-up's??.....?

I don't understand why I am still getting bombarded with pop-up's even though I have a pop-up blocker (the one on the yahoo toolbar) enabled. I have it set to block all pop-up's but I still get them all the time. I cleaned out my temp. files, cookies, and I've done scans for ad-ware and spy-ware............ is there any way to stop the pop-up's?