Thanks Joe/ Ira. Unplugging/ re-seting the hub, seemed to do the trick. Hub was culprit. Don't know why it went weird overnight. but ok now.
Untrapped power surge or dropout is the most likely explanation. I have my hub plugged into an uninterruptible power supply for that very treason. On the other hand, It could have just been bad karma, (I recently re-learned the SMC reset trick because a port on my Mac mini quit working and it is on an that same uninterruptible power supply.)
