I had this with my SD7, but it went away a bit when I switched down to some crappy old Promax arms. I guess you don't wanna do that though. Make sure your pads are dead square, horizontally, and bear in mind they'll likely need a bit of time to wear down to the right angle to hit flat (vees don't push square, unless you have one of those parallel-push ones... which the SD7 is not ). Set the springs to the lowest tention possible, but so that they still pull the arms back out quick enough. If it's easier to pull, you'll pull it harder, which might mean more bite. As for the cable - many would scoff - but I have yet to find a better cable than a Wilko's £1.70 jobby.