It appears the only way to "coax" it to render is using one of Masa's tools, or an object editor like milkshape or max. In fact, the reason I think it doesn't outright render can be seen in milkshape (maybe it's just a flaw?). The hair parts appear as large triangles...

Oh well, looks to be working fine in Poser 5, that's all that matters to me.

The above image is the ball prop with hair processed through Masa's FurFur tool.