from the sounds of it you have just had cable bb installed, is that right?
if you have then thats the reason. that
Netgear DG384G router you have is no good as it's an adsl router/modem.
for cable bb you need a cable/dsl router, you could look at one of these
Linksys WRT54G as it's one of the recommended one's on here. although i'm sure that ppl could recommend others.