I'm running  two  30 g bfl miners and 10 block erupters   with a Pi ---  and 20 erupters on  another Pi    i'm using  d link  hub for most erupters  and an orion 10 hub-----  is working great but every 2 days or so one of the pi miners  shuts down  any suggestions
Check on your power supply, usually thats the problem...
this  .  what are you using to power the little singles? if it is the stock power supplies they are not that good. If you are in the usa pm me I have a ton of used but good pus's.  if you want a new psu I have a lot of links for low cost psu's