OS X 10.6.6 and “adb devices” fails to list android devices

Question

adb devices was working fine last year, but after upgrades and new software installs, adb devices no longer recognizes USB attached Android devices.

Her

Answer 1

Another alternative: on modern Apple iMac's, the USB port closest to the outside edge of the machine never works with ADB, whereas all others work fine. I've seen this on two different iMacs, possibly those are USB 1.0 ports (or something equally stupid) - or it's a general manufacturing defect.

Plugging USB cables (new, old, high quality or cheap) into all other USB ports works fine, but plugging into that one fails ADB

NB: plugging into that port works for file-transfer, etc - it's only ADB that breaks.