Brian,
I had similar trouble for a couple of days. I'm running XP pro and use IE explorer to access the internet. I originally thought it was my computer and after I discovered it was not I contacted my ISP. They told me that it was a band width issue.
Long story short, from Toronto ISP's purchase band width from major service providers (the ones who own the cables). If you are with a very small ISP who has limited band width you will likely have slow downloads and other problems.
Fortunatly my ISP has upgraded their band width and all has been fine.
I hope this is a little useful to some.
Cheers,
Mike