Scrolling Down Threads is Too Torturous!

I have just rebooted my com and there's this problem which is bugging me. Everytime i scroll down a page, the whole thing will lag like hell and like keep refreshing, and its slow! Imagine trying to scroll down a long thread having to put up with this.

I have look into control panel but just cannot find anything to fix this. So please tell me how to get this off. It's pure agony!!!

PS apologise for my lousy description but i see whether i can make it clearer when u guys ask

Possibly the orange Vonage banner ad with moving snowflakes in it is causing your computer to choke. This 726x90 clumsy Flash banner ad takes almost more ressources on our computer than a modern video game. If you reload the page when you see that ad it sometimes disapear replaced by a different advertisement. Which kinda defeat the purpose of banners in my opinion, because the accumulation of each page refresh will eventually cost them more than the banners ad earn them. They should fix that.

Tx for the response.

I have to admit i'll have to do something about that pathetic 256mb memory soon, but its was not like this before i rebooted it. And be rest assured it's not any ad banner, this problem exists thru the whole internet for me. Its like the page needs to reload the contents of the page.

I reckon it got something to do with some setting on my com which is unknown to me. Help, anyone?