I was having the same issue and mine also seemed to happen when I was in an area with poor service. Never could get rid of it so I let Verizon replace it under warranty, of course only after I odin'ed back to stock. Before I replaced it I tried everything from going back stock to reflashing other ROMs and never could get rid of it.
Todd - is the replacement working better or do you still get phantom presses?? It seems like a software error instead of a hardware problem since I never had this problem before switching to CM7.