Problems with Antminer U1 - why doesn't it work? I've got other Antminers working, this one just throws these errors in debug mode - is this fixable?  

[2014-01-30 19:03:10] Bmsc send golden nonce
[2014-01-30 19:03:10] ANT0: GetResults (amt=0 err=-7 ern=110)
[2014-01-30 19:03:10] Bmsc Read: No data for 101 ms
[2014-01-30 19:03:10] Bmsc recv golden nonce timeout
[2014-01-30 19:03:10] USB uninit ANT0
[2014-01-30 19:03:10] USB free ANT
[2014-01-30 19:03:10] USB unlock Bitmain 1-5
[2014-01-30 19:03:10] RES: Bitmain (1:5) lock=0
[2014-01-30 19:03:10] USB res unlock Bitmain 1-5
[2014-01-30 19:03:10] BTM looking for ANT 10c4:ea60 but found 0e0f:0003 instead
[2014-01-30 19:03:10] BTM looking for ANT 10c4:ea60 but found 0e0f:0002 instead
[2014-01-30 19:03:10] BTM looking for ANT 10c4:ea60 but found 1d6b:0002 instead


I'm running cgminer 3.9.0 from the fractal branch, though all the versions that support the antminer-u1 seem to have the same results, so I don't think it's necessarily the miner software.  I'm running with these options to underclock:

--bmsc-options 115200:20  --bmsc-freq 0681 -D
I had the same error "Bmsc recv golden nonce timeout" after to try Windows10 Install. So I reinstall Zadig drivers, and reconect my U3. So works fine again.
I dont know if is your case, but:

To reinstall your Zadig (http://zadig.akeo.ie/):
1) choose Options | List All Devices
2) Select CP2102 USB..
3) Choose "Replace Driver"