It's been observed on different versions of BOINC and it's attempt to find the shortest jobs. Most often there is a form of deadline contention... possibly you have received FA@H jobs with a short deadline with later deadline jobs still in the queue. It happens most frequently to those with larger buffers. Make sure to untick the "Leave in Memory" so the job switching happens only at checkpoints and unloads from ram when is does pre-empt a job. That should be loss-less on CPU time from BOINC version 5.8.15

Oh, and usually it happens in the first few minutes of a job whilst the agent tries to determine the real estimated run time. It will go away once the EDF status is cleared.

cheers

Thanks...After getting off work today I sat down and started
looking closer. There's so much on these forums I can't ever
get it all read ! !

Anyway, that seems to be it...I am getting work units with about
half the time to complete. I store about 2 days on my computers
and when the shorter units appeared at the bottom, all of a sudden
all the jobs at the top of the list began getting put off in favor of
the sooner completion times.

Not sure how many of these there are, but I went in and reduced
the number of files I will cache, just in case, that way I won't risk
not completing the others in time.