I just started having this problem myself, now when it dies (a drop off point) instead of restarting it eventually stops and just hangs.  I'm assuming this has to do with one of my 6 miners being defective, so now the hunt to narrow it down begins.  I'm using a powered USB 2.0 RHB 520 10 port hub with MinePeon/R-Box's default image and while it ran fine initially, it now will not go more than 30 minutes.