Hey there!
I'll try to explain it the best I can. I have a 5Mbit ADSL connection through Qwest. For some reason, in the past week or so, I am unable to visit a specific website that checks to see if you have high speed or not using some sort of Javascript. If it detects that you have a slower connection than required it doesn't let you access the site, otherwise it lets you in. In troubleshooting I did the following:

1. I re-installed my computer, and applied no updates or patches.
2. I tried a different ethernet cable as well as a different DSL modem
3. I tried 3 different computers on my network

From what I have found out it has something to do with my connection. After hours of frustration, I took one of my computers that couldn't access the site, and took it to my office which has a 1Mbit ADSL connection. Using this SLOWER connection, I able to connect to the site fine.
I would appear at first guess that their site isn't running the detection properly. I guess a question for anyone out there, is there a way for me to SLOW DOWN my DSL connection? I have a Cisco 678. I'd like to slow down the connection to 1.5Mbit to test.