They play fine for me, so don't blame the subbers because you have a crappy computer.
Really, my guess would be you may need to get an updated version of XVID or ffdshow - I'm not sure why, but many subbers do have a perverse love of using bleeding edge beta/unstable codecs. Oh well, can't complain too much about new codecs - at least it seems most groups have finally given desiccated corpse of nandub's SBC a much deserved burial.