Done a bit of searching and apparently a lot of Linksys routers don't support 100mb on the WAN port. Personally i swear by Belkin, work perfectly, £55 in staples for a 54g one
HTH
---------- Post added at 17:55 ---------- Previous post was at 17:53 ----------
Also try this:
From a forum:
It is an MTU issue. I had to change mine from AUTO to 1485. Works fast now.