Virgin Broadband Speeds

[TheDude]

I recently upgraded by Virgin Broadband Service from 10mb to 20mb, I gues that is where it all went wrong !!
I run a small home network of computers, all hardwired to a Netgear router, and on 10mb I was getting a download speed of @ 8mb on average. (Obviously decreasing at peak times).

Now that I have 20mb download speeds (theorectically) I can acheive 11mb. I did once acheive 14.5mb, but this was by disconnecting from the network, and plugging directly into a PC.

I obviously have an issue with Virgin as I do not believe that the speed I am paying for is being attained, but their attitude at the moment is that the drop is down to the router. I have expalined that if I was getting 18-19mb download speeds in the first place, it would not be an issue even if there was a decrease through the router.

I have read countless forums, but cannot seem to get a definitive answer with regards the drop at the router.
I am using a Netgear FR114P, with the PCs running XP.
Everything is hardwired, don't want any wireless thank you !!

Does anybody know if it is theorectically possible to acheive 20mb on my network as it is.

I undersatnd their is a Gigabyte networking standard which is faster, do I need to upgrade.

Would appreciate any advice, and now back to the Virgin Customer Service to try and get some progress.