FSA trouble

When ever I try to render anything with the new FSA feature (save buffers->full sample) (yes, it’s an svn build), blender crashes and spits out this to the console:

blender: symbol lookup error: BlenderSVN/blender: undefined symbol:

Anybody know why? It sounds like it’s missing some library. It’s a 64 bit build running on gentoo linux 64bit.