Continuous internet browser timeouts

Hi,

I've been getting a weird slow down problem when browsing the Internet with either Safari or Firefox that seems to be a bit random. I can browse the web fine for a while then all of a sudden pages will just time out. After a few minutes everything starts working fine again. Sometimes it's random but I can force it to happen by opening a lot of images, for example a Google image result search or Facebook, and it happens a lot while browsing www.tomshardware.com. It doesn't always happen immediately but if I continue for a few minutes this issue will occur.

While these pages are timing out I've tried disconnecting from the network and turning off the Airport card on my Mac then reconnecting but this doesn't make any difference and the network access is fine. I also tried pinging a website like google.com and it timed out. I can view my routers admin web site at this time and it shows the ADSL 2 connection is up and has no issues and torrents running in the background are still downloading.

I can download files directly from a link or through a torrent program and run them all night without this issue occuring. It only seems to happen while browsing.

I also have Windows Vista on my MacBook with IE 7 (through Bootcamp) and I have never had this issue while browsing in IE 7 even when I try doing the same things that cause it in Safari.

I'm using a 13" MacBook Black. My internet connection is ADSL 2 with a Belkin modem router connected via Ethernet to my Airport and my MacBook is connected wirelessly to the Airport. This issue happens in both Safari and Firefox. I've run Software Update to download and install all the latest patches for Safari as it's my main browser.

I know this kind of topic has been done over and over but I can't find anything like my particular situation so any help would be very much appreciated.

Thanks.