I think its probably down to the quality of the links, how far they have to travel to you and how many people are viewing it on the way. Vlc is able to show the stream slightly quicker than sopcast can, so if the vlc work around does work for you then that is probably the problem. It shouldn't be like that for all streams, its just the luck of the draw, I have had to use this method myself in the past both on Vista and XP, it is a bit of a pain but its better than nothing.