Opera 12.00 Alpha Build 1116: Very sluggish on a certain recently revamped website.

Hello, I would like to report that Opera is very slow on this particular website.
http://download.cnet.com/windows/
I tested other browsers like Google Chrome and it runs on the website very quickly being the most responsive. Opera on the other hand is the most unresponsive, or sluggish. Mozilla Firefox 7.0.1 runs good on the website too with scrolling being responsive, only being unresponsive while the web page is loading, however, once the web page is fully loaded, scrolling is very responsive, but Opera Alpha 12.00 Build 1116 is not very responsive, though not as bad as IE8. IE8 is very slow as well, but this shouldn't be no surprise, and not really important as it is outdated. I have no hardware acceleration on this computer for Opera Alpha 12.00 B1116 as I have a very old graphics card that Opera can't utilize very well, so it's blocked. When you scroll around the web pages of the website, you get high CPU usage over 90% CPU usage with also very laggy scrolling as well even when the web page is fully downloaded. I have a old computer, Windows XP Professional SP3, 2.53GHz Pentium 4 Celeron processor with 1 Gigabyte of RAM. Can anybody confirm this by going to the website? The website is also not very responsive with Opera 11.52 official version. Opera scrolls very choppy on it.

it seems that the top bar/header of cnet is causing sluggishness.
I have a test too,
go here
www.italiansubs.net -> scrolling speed in opera 12 is much faster than google chrome, maybe opera 12 supports more flash gadgets on the screen than chrome does?

while if we try
www.gamesvillage.it opera 12 is not responsive at all, it seems like that all the stuff in the top page slows opera down to hell and it sucks tons of cpu cycles, google chrome instead in this page behaves much better, and is decently usable.


I have hardware acceleration enabled both google chrome and opera12
I would like to know the reasons

Opera smooth scrolling slow work with some css, overflow hidden, background fixed, ...
This old know problem, but not for Opera devs