Mine does the same, it started out of nowhere!
I have been running it just fine with WMV files for atleast 6 months now, and just 2 days ago it started buffering on every single WMV file!
Nothing had been installed, no system patches/upgrades, no settings changed, no version upgrades, absolutely nothing running except IRC during the time it got bugged. :?
It sucks now trying to skip through files quickly, talk about damn annoying. :(
I love BS Player but this is such an annoying problem that even the crappiest player (WMP) doesn't experience.. I don't want to have to ditch something I've been using on multiple PC's for over a year.
Help someone ! :)