A lot of the time, when you think your connection is slow, it is in reality something that is "upstream"from you that can bog your response time down.
If you have a traceroute utility, such as Neotrace or visualroute, you can see the response time of all the routers/hops that you go through to get to a particular page or destination.
Even thought I am only on 56K dial up, when things really slow to a crawl, I fire up visual-route and see where the bog is,and almost every time, you will easily be able to see where the problem is.
For example, you see response times in the 200 to 500ms range for the first three hops up, but when when you hit the fourth, SMACK! into a wall at 1300 ms. Your connection is speedy as well as the three up from you, but they still rely on the dog a$$ slow fourth hop, so it seems that your connection is slow because it's waiting on data that has yet to arrive.
I have had connectivity problems before, and looked, and can tell what carrier is having problems, and have seen routing loops that cause you not to be able to get to a page because one hop passes info to another, who then passes it BACK to the first, who passes it back, and on and on.
So, there are somethings that are not within your control that can cause you loads of grief, and if it's an upstream problem, about the best you can do is hope they get whatever it is thats FUBAR fixed.
