Firefox 35.0.1 (released January 26) doesn’t handle order independent transparency. Firefox has added support for the EXT_blend_minmax WebGL extension, but at the same time something with additively blending on floating point textures has stopped working.
Under Linux FF 35.0.1 everything is working fine.
We are doing some research, but probably we just need to wait for a new version of FF with this thing fixed.
So far we recommend to use Chrome or IE. Also sorted transparency works.