[G5] slow internet connection speed

[Jerry Bunn]

I'm running OS X 10.3.7 on a dual G5 with 1 GB RAM.   I am using Time 
Warner's Road Runner cable internet.

Lately I've noticed a slow down in connection, so I used several of the 
test sites on the internet to check how fast or slow my connection was. 
  I'm getting speeds of between 51 kbps up to a max of 328 kbps.  I used 
to get over 1000 almost all the time on my old computer, dual G4 using 
the same Time Warner.  I've called them and they've had me run a couple 
tests, like "Trace" test, restart computer and modem and still no 
change.  They tell me its my computer.  I just cannot believe that.   
My friend, using a local cable company, tested his 7 times and his 
range was 786 - 1228 kbps.  I should be at least that fast.  Anyone 
have any other ideas as to why my connection is so slow?

Jerry