Yes you just might have the mounts the wrong way round.The mount with the slight flat spot should face down to the frame and the rounded one should face upwards.Just don`t tighten your bolts up too tight because when i did that with mine it bottemed out on the frame and snapped in the frame so I had to drill it out but that was with those rubbishy orange monty bolts :( .
Thanks
Deonn.
P.s do you use a booster.