Running out of work can happen if the server is slow or the network between you and the server is slow or down. At one point today there was 20% packetloss, probably due to a problem at the data center, which would cause such a slowdown. This should not happen often.

The message about not getting any results happens if the device was given lots of work but found no results. It may be that the work it was given simply didn't contain any valid proofs of work for it to find. But it can also be that the device has failed for some reason. Because the Icarus protocol is very primitive, it's impossible for your computer to tell the difference. So it sends the device some data it knows that it will respond to, and looks for that response. If there is no response even then, that means there is something wrong.