Okay, I have the same kind of issues. Except here's my deal:
It's that new Linksys N-Router, with up to 1GB of UL/DL
It's got 7 wireless computers connected to it
It's giving me like 10 KBPS without other computers actually even being on
And it's killing me
What is the problem
Oh also I've reset it twice, it shot up to 900KBPS but that's still like nothing (and then it shot right back down soon after)