I still do wonder about the high percentage of IOERRORs of closed ORconnections (as seen in page 1#5 of the arm tool window, press e + q). May I ask here others about their experiences ?

The issue is already filed in [1]. [2] contains a python script I used to monitor the issue directly (instead using arm).

[1] https://trac.torproject.org/projects/tor/ticket/13603 [2] https://trac.torproject.org/projects/tor/ticket/13603#comment:10