Strange, make sure in spybot and ad-awrae you update and than immunize, than scan again. Could also be a trojan thats lettin them in. Than do a scan at http://housecall.trendmicro.com/
Little tip to people also if you didn't do this, keep your favourite firewall,AV and spyware scanners on disk. Disconnect from internet before installing windows and install all your proggies before connecting or you will get nailed
One thing i forgot one of the favourite hiding spots of the real nast stuff that causes popups is your hosts file. Location and what it should look like are below. If there is spyware in it you will see it
Windows XP = /windows/system32/drivers/etc
Windows 2K = /winnt/system32/drivers/etc
Win 98ME = /windows
Open up the hosts file with Notepad. Below is what it should look like:
-------------------------------------------------------------------------------------
# Copyright