Todd,
It's very possible your local phone company could be the culprit, or it  
could simply be the wiring in your house. A call to the phone company and a  visit 
from a technician would answer your question. A friend of mine had the  same 
problem and the phone company's answer was that yes, it was their equipment  
that was the problem, but they were providing a voice service and that was  
working fine. He got a Direcway satellite dish and had the phone  disconnected.
The newer V92 modems might help with your problem, but then again it might  
not. $11.49 would be a cheap investment if it would work. When I had dial-up, I 
 was able to connect consistently at 53k. I've used this modem in all the  
computers I've built over the past couple of years. Been very pleased compared  
with the US Robotics.
 
Rummy