Wireless slooooows

Hi
When using my laptop, if I open different web pages and follow links, my
connection slows to a complete stop after a few minutes. If I stay on one or
two web pages it is fine. Even when my internet connection is totally dead,
my status is 54 mps, connection excellent. I have tried changing channels,
no difference. The router is a sweex, connected by cable to my main pc.

It is as though surfing through a lot of pages fills up some sort of cache
? This happens with I.E.7, Firefox, and Opera.