I have a 2012 MBP retina display. Over the past few days I've noticed that my trackpad has started to become finicky: it's hard to pinch, the cursor occasionally "jumps" and sometimes gets stuck so badly that it can only move on one axis (e.g., can only move left or right). After restarting and resetting VRAM things seem to momentarily be fixed: but I don't know if this is strictly power of suggestion. The fact that the cursor is stuck and that restarting helps fix the problem implies to me that the problem may be in part software related.
I've seen previous threads that suggest replacing the cable and that this was a frequent problem in previous generations of the MBP. My mac is still under warranty, but I wondered if there may be any software causes that I should investigate.
If things don't pan out, I can always take it to a store.