The other one i use when J@CK TV get a bit jittery is "BritishTV"
http://www.myp2pforum.eu/live-tv/41045-british-tv.html
Same thing but uses VLC instead of media player. It also uses mms streams as well.
Quality pretty much the same.
The picture freezes because the buffer in WMP needs to be increased especially if your bandwidth is less than 10Mb/s, or if there is a dodgy router between you and MrVeryKindtoShareHisSKYBox´s server.
The forum has loads of advice about sorting problems out.