Is this with the S4/furious? That should be a long enough bow that cables rubbing the cam shouldn't be a problem. If it is then maybe convert the bow to a Furious X system and this will definitely take care of that problem.
If it's one of these ultrashort bows like the Cheetah then I'm afraid you'll have to live with one or the other. The angle the string comes off the idler to the cable slide is just too much to get a clean roll onto the module. Such is one of the problems with these short bow and present cam designs.
Now Martin would just change the module a bit and machine the grrove on a slight angle to match the string angle this potential problem wouldn't be one. I honestly don't have an answer to the angle coming off the backside of the idler wheel except to quit shooting single cams. Most of them have this problem.
If You're Not Living on the Edge You're Taking Up Too Much Space
Martin/Rytera Staff Shooter
PSAA Life member, UBP Life member
PADI AOW Diver