The only carbon frame I would trust would be one from one of the major players like Trek, for example, with a huge R&D division and computer modelling of the laying up/forming process. Riding a cheapo frame is like cheap insurance - the only time you realise it's no good is after the crash!
http://www.alibaba.com/product-gs/519852863/2012_new_mtb_frames_FM056.html
Scroll down to the bottom, there are photos of them "testing" the frames.
Hong Fu also honour the warranty and replace the frames if they break (which isn't often) if you have a look through that MTBR thread.
