Tried a windows version of 2.8.2 on 1 x CM1 + 1 x BFL Single on Win7 x64.
It starts as usual, attaches to stratum and makes a look of hard working, but never makes any shares, just takes Icarus Re-estimations periodically.
Ran it for 5 minutes - U is still 0, no shares.
O_o
Got back to 2.7.6 through mining proxy - it works well as usual.
I get this result as well. Each single shows a hashrate and cgminer reports about 35 work units, but U is a constant 0. Pointed to mine2.btcguild.com:8332, using the Windows binary.
That's most unusual. I assume it only happens with stratum? What does cgminer say when you run it with -D -P -T (note the output will be very verbose so try it only on a single device first)?