Okay, finally something to update to this matter.
First of all, for a background info, I started using Chrome as my browser due the fact that it's faster, and more simple. (I don't need all those bells and whistles IE and Opera has). Since then, the amount of Clicksor ads got to the sky. Basically, I wasn't able to view single page from here without having all those ads. But again, the problem was only in GB, nowhere else did I see those.
I contacted my dads friend week ago, as I was getting really annoyed, and he told me that it could be virus, and he could check my computer, but it would take couple of weeks before he would be able to do that. Instead, he suggested several things for me:
1) Clear all IE cookies both through the browser and manually. This didn't help.
2) Do the same with Opera. Again, no help.
3) Run three different commercial programs (F-Secure, which I already had, Kaspersky and Norton, and the guy was able to get me demo license for full features lasting two weeks). Couple of viruses found and destroyed, but didn't help.
4) Run Avast. I had already done that, and it didn't find anything, but decided to do that again, this time turning off my internet connection. Left it running while I had work shift, and as I just returned, it had found one troijan. Booted computer, and no trace of Clicksor so far.

So I suspect it was actually virus causing all the trouble, and very nasty one as I had to run 3 different commercial programs and Avast! twice before solving it. So far, even while using Chrome, seen no trace of it, and yesterday it was infesting every page of GB.
Also, not sure if it has anything to do with matter, but as Clicksor is actually java based thing (figured it out with Chrome, as it shows what it loads better than IE and Opera), and I had java disabled totally in IE and in some extent in Opera, I had only now and then the ads, but as it's not possible to turn java off in Chrome (something to do with how Chrome works and makes it faster), I got it all the time.
Yet, even though the problem is solved, I'm still rather curious why GB was the only place showing it?