I don't know how handy you are, but many of us have cut the plastic where it broked and added metal hinges. I've done this to all three slides that have had this problem. The hinges easily satisfy the bends at the places where the plastic was known to break and I've had no problems anywhere since. Here's a photo of what I did. I used a 4 inch hinge, machine screws and nuts, and some washers (on the back sides).
If you'd like more details on how to do this PM me or send me an email.