No problems with my superbes but if you are using a super stiff outer cable like Jagwire sometimes you will find that it actually pushes down on the brakes making them go to one side. Getting the length/loop right doesnt always work so just use something on the handlebar to hold up/pull/push the cable in the right direction.

Rebuild them if you haven't already, there are alot of sufaces contacting each other which can cause problems if they are not clean.