The miners that did not work were an ASICMiner V3 Erupter Cube and a BFL Jalapeño.
I'm using a BFL Jalapeño with this version - we've probably got a backend behaviour here - one thing I would suggest is starting the BTC miners BEFORE starting the gridseed miners on LTC mode 
If that's not it, I wonder whether it's an issue with the proxy for the cube
But it is really late for the those miners, they are no longer profitable at the current BTC price with poor luck so I am shutting them down in the next week. My electricity cost is $0.08/kWh.