Crossfire problems

[silverstone08]

hello all
my system specs are intel i7 860 at 2.80GHz
two ATI Radeon 5750 in with crossfire cable
(theirs anything more required just shout)
my issue is that whenever i activate crossfire and try to play the game reather than the performance increase im expecting i get a massive performance decrease (about a 10th of the fps at best) and this is both full screen and windowed onthe exact same graphics settings i dont know whats wrong and its really annoying please help me

thanks for reading and hopefully responding