Fine for networking, horrible for internet access

I've bought the wrt54GR to replace my D-link di-524 (which i paid 20$ for comparatively to 100$ for the wrt54gr) My network works fine but my Internet is extremely slow. I have a cable modem hooked to this router and it feels like i'm connected to a 56k modem. I ran tests on bandwidthplace.com and got 200kb/s while i was having around 3.5MB/s with my dlink router. I talked with technical support but it didn't help... they told me to return it under warranty. The thing is, i know it's not broken, it just doesn't work. they designed it badly, that's why a 20$ dlink router does a better job than this 100$ router linksys don't care about(the only firmware made for it dates from November 2005, no update has ever been made to it).

BUY A D-LINK