router slowing int

[mke]

Hi,

I have virgin media 20mb internet, when this is plugged into the PC directly it works fine giving me full speed all the time. I have a cable router Linksys WRT54G which is plugged into the PC directly with ethernet and doesnt use wireless, when this is plugged in the speed is random. If I do speed tests or download anything the speed results will be 6mb, then 2mb, then 20mb then 10mb etc and not a constant 20mb.
This router can apparently support 20mb throughput.

Any help would be greatly appreciated.

 

[pjumpleby]

could be a number of problems, i have had this happen to me but not at such of a loss of internet speed. could be a firmware problem, router settings (firewall, routing, etc...) or even a dodgy cable.