You probably are not getting as much bandwith as you think. If you are on dial up, and you have a top of the line (or bottom of the barrell) 56.6kbs modem, you never get a full 56.6kbs upload or download speed. Same with cable, the local cable company boasts "up to 5mbs speed!", when in all reality, you only get about 4.something. I'm on a restricted (cheaper!) version of broadband, capable of "upto 2.5mb/s speeds!"....but I top off at about 1mb/s on most sites (games and test sites included).
Also, I know that with a dial up modem, and with cable connections, the more "splits" or "junctions" that you have in your house, the lower your speeds will be. I'm not sure about DSL, but I should think it would be the same. When I was on dial up, I had 2 phones in the house. I installed another 2 phone lines, and lost 8kb/s on my connection

. It also depends on the lines that go into your house....last year someone hit the pole that holds our cable line going to our house. It had a splice in it, and I told them that I wanted to replace it. I gained about 10mb/s just from gettng rid of the splice with a new line!
Something else that might help you is to turn off anything that "auto updates", like java, AOL, MSN messanger, windows, Mozilla Firefox etc. etc. When these programs are searching for updates, they're also sucking up precious bandwith. It will also help to shut off anything running in the background (including things that startup when windows starts that aren't neccesary), this will help to free up some resources, mainly the processor, so that the computer can focus on running the game.
Hope all this helps!
Love your sig BTW