Green/scrambled video when using 16bit colour

[Velmias]

Every video I play in BSPlayer when my desktop has 16bit colour depth has a green, snowy and scrambled picture. If I change to 24bit it works fine, but then the video is choppy because of my PC's crappiness. I need to run at 16bit for smooth video, and everything works great in Vdub, WMP etc in 16bit, so why can't BSPlayer handle it? I've mucked around with the options but nothing has fixed it.

Here's some screencaps