It means that BOINC is using earliest-deadline-first scheduling because your computer is overcommited. ;-)

Basically, you have got more work queued than BOINC thinks you can complete before the deadline. So, to give you the best chance of making the deadlines, BOINC is doing the work with the earliest deadline first.

It has nothing to do with your lost progress. That is normal. Work units only save their progress periodically.

If he only runs part time he may be missing some checkpoints, noted as lack of progress. Some of the projects run a long time before a checkpoint is reached, and if he doesn't get there before turning off the computer, the workunit could start over. That particular workunit could be taking a checkpoint at every 15%. If you turn the computer off at 29%, it will restart at 15%. It is not exact. Every project is different. Some make it easy to notice a checkpoint. Others do not. BOINC is working on some mechanisms to wait until the next checkpoint to turn off the computer.

I just leave things on all day/night 24/7 unless there is a lightning storm or I am not here.

If he has lost work during the week due to missed checkpoints, the same parts could run over and over. It becomes more likely that the "using earliest deadline first scheduling because computer is overcommitted" will kick in.

If computer time is limited, try running some other projects that may have more checkpoints per workunit. I don't know which one he had a problem with. The WCG project list in "My grid" is used for BOINC. The project list in the device manager is used for the UD.EXE version.