I am using the Arduino IDE in Windows. I have noticed that if I leave the Serial Console open (the Serial Console launched from within the IDE) and I power cycle the Galileo board, I cannot ever see the Galileo listed in the Serial Port list.
The COM port for the Galileo is still seen by Windows, I can see it in the device manager, but it does not show up in the Arduino IDE. I have tried restarting the IDE, but that does not fix the problem.
The only thing that fixes it is by restarting the host machine. Which gets annoying after the 12th time of doing that.
I hope this can be fixed in the next revision, or that someone has a known work around for this problem.