I shoot a Liberty and have heard of problems like this in the past. I'm not sure if all bows have this problem but it is a problem. Right now Bowtech is switching string companies, but I don't think they have done it yet. I haven't had any problems with mine yet, but I heard that if you push the serving back into place with your finger when it comes loose it will start staying in place better. I'm not sure what you can do about the frayed string.

Good luck