man! i got same thing tonight! a "click here" button was installed on my desktop and always come pop-up at like 5 minute between each, it was a lot worst before i delete something in "system 32" was the "click here" button named canada something !?! now i just got a pop up that tell me that i got pop up
all i can tell to you is run your spyware program like ad-aware SE , thats where i found
that one, just look where they are and try to delete them, may be you already do this, but, i hope this help, "spybot search and destroy" can help too.
good luck mate