it may also be your pc - if it has alot of crap running in the background then it's going to slow things down. keep on with what Jaymie is suggesting to test your network but also try;
start > Run
type : msconfig and then hit enter.
click the stratup tab and it will list every application that starts when you boot your pc. get rid of anyhting they you dont need (itunes etc) and your pc will run a little faster after a reboot.
a quick test that this will work is;
in task manager, right click on explorer.exe under 'processes' tab
click end process tree. this will close almost every application that windows does not need to run, with the exception of security software. your screen will go basically blank so dont worry about this.
then in task manager click applications > new task and type explorer.
it will re-load the desktop clean of any background software and then you can test the streaming again.
also, do you use any IE toolbar ad-ons?
if its not network or software, i'm afraid you need an upgrade buddy.
