I try ethminer first time. Hardware: NVIDIA 750M w/o screen. Software: ethminer master GIT (May 2016).
In first run, it got 2 accepted in first 10 minutes. Then no one in 1 hour.
I've restart ethminer and start watching log. Accepted: 2. When it found third solution, it says "Solution found, trying to upload... Fail. Retry in 1... Got new work". Can it be a reason of no result for 1 hour?
Then I've remove ~/.ethminer and restart. After that, I saw:
Bad worker creditials?!
I restart ethminer and wait first solution. Now worker is right.