You have to wind teh screw out (its accesable from underneath teh grip frame, behind teh trigger, if you remove teh grips) to actually fit teh trigger, they may have left it out too far.
aran i had the same problem my cp roller trigger got stuck back there aswell, and as skeet sed there is a screw u need to wind down. cp roller do have a lot of the side to side but ilike it anyway
aran, do as the above suggest but sometimes you need to carefully widen the top of the frame with a screwdriver or somesuch. Had to do it to my GF's gat and it's been fine since
Yeah..CP triggers are made to better tolerences than Ion frames...you can open up the trigger groove at the top of the frame with some abrasive paper or a fine file etc.