yours sounds like its a hub problem more than likely you hub can only power 7 erupters
I have 2 hubs. I am running 5 BES on the one and 3 on the other. The one hub has a power adapter rated at 3.5 amps and the other hub rated at 2.5 amps. So power is not an issue and I am conginesent enough to not overload a single hub.
I will have to concur with the below post although I do not have the luxury of win7 at the moment.
WinXP has issues with managing multiple duplicate devices. Lots of people have issues and I have not seen a definite fix for it. I have been able to get 8 or 9 working at the same time unplugging, plugging reinstalling etc. but when I went to 11 I was never able to get them ALL up at the same time so switched to win7 and never had an issue with them all running at once since.
The problem has really been a "nightmare" and I wasted an entire weekend installing, reinstalling, rebooting, unplugging, replugging...the whole 9 yards. Became this entire OCD like routine. I began pouring into research on Windows Dev on USB's, USB controllers and Hubs.
So long story short, I stumpbed across this program called USBDeview found here -->
http://www.nirsoft.net/utils/usb_devices_view.html I learned that a number of devices were showing up as the same device as stated here ->>
the problem is all the be's have a serial number of 001 , that link i posted above, you can download a program and reprogram the serial number on each BE. then you will not have hardware conflicts. To me thats a pretty definite fix. Once they each have a different serial number , windows xp no longer throws the hardware errors.
In conclusion, I was never able to get the 8 BES running on 2 hubs to hash on one machine. Even after using USBDeview to unistall a specific BES from my PC's ledger It was still buggy as hell. So after a weekend wasted, I was satisfied to get 5 BES hashing on one machine and the other 3 hashing on an entirely different machine. Im just happy to be hashing and not loosing
BTC. Now im afraid to even look at the things the wrong way. The 3 BES that are hashing are still throwing a ton of Hardware errors (3.3%) but it leads me to believe its a hub issue. I will have to check out the above mentioned program of rewriting the serials.Thanks.