I've been using browse for a while now and it has always worked fine for me.
What build are you using? Where do you place your anis, and what do you name them?
I've used 3.6.10, 3.6.11, 3.6.12 RC1, hud folder and I name them whatever I want
It is perhaps more interesting to ask what method you used to create your frames into .ani. I use that old little program anibuilder with the advanced settings on: 'Mainhall animation (makes all frames keyframes)'. (Though that wouldn't explain why black wolf's ani's dont show up for you)
An other possible cause is having a wave file selected in FRED that is too short. It will cut off the .ani if it ends before the .ani does. Be sure to keep Persona to <None> as well, see if that makes any difference.