can i ask you a question... my 256sl and x0 cranks like yours i guess... did you used any washers mounting the crankset?
another thing on one side the bearing sits there and problem solved, on the other side (non drive side) the bearing moves outwards (it does not get out of the frame, but comes out of place) just by removing the arm, so i guess is not very tight there. I read you come up with something like that... now i have some noise coming from the BB. In your case how's it going? any suggestions?