Really short version: The more you can isolate these on the network the happier they'll be.
Short version: There might actually be something to that "get the Androids off the network". Running for 2 days now at above full rated speeds, just in time for the Slush pool to have a pretty good run of luck. I'm currently showing 106GH/s on the pool - my theoretical maximum for 2 at 38 and one at 30.
Longer version: I didn't think the Android issue would apply to me, as I don't use the wireless access point as my router, and the cubes and the wireless access point (and thus the Android machines) are on different network switches.
The issue with Android is using IP addresses after the DHCP lease expires, not traffic. See DHCP client ignores lease time:
https://code.google.com/p/android/issues/detail?id=11236.
So, a good solution is to put the Android devices on a separate logical network. If the primary network is 192.168.1.x then create a second network such as 192.168.2.x (both with a net mask of 255.255.255.0). Unfortunately that means two routers.
Is this what you did with the second router?