I have the same problem even now on the latest version of bsplayer 2.57 and I can't find a solution to it I tried to use different codecs like K-lite mega codec pack and shark007 codec for windows 7 but without any good result I also tried to use ac3 filter instead of ffdshow but it still crashes after a movie has finished and I click on the close button or when it's going to switch from the movie cd-1 to cd-2. I'm using windows 7 service pack 1 x64. Because of those crashes I'm using a different player now, hopefully the devs will fix it on the next version.
Forgot to say: when I use bsplayer 2.57 on windows xp sp3 x86 it never crashed and I was using the same codecs so my guess is that the bsplayer has compatibility issues on windows 7. The setting that I use for the video rendering is "Internal renderer direct draw surface".