Shows play ok but the commercials are all laggy or choppy or freezing? This was driving me crazy for such a long time, and I finally found what seems to be a good fix.
Well here's the silver bullet, go out to an administrative command prompt and enter:
netsh interface tcp set global autotuninglevel=disable
The docs say "disabled" but this command worked for me in Windows 7 -- issuing the command returns a reassuring "Ok." response. Note that this setting does not "stick" when you issue it from the command line. Either run it in a batch file, or perhaps I'll figure out where to change this in the registry to make the change permanent.
Huzzah! No more annoying jaggy commercials. Fixed!