Updated my iMac to Mountain Lion on Sunday and this old wifi issue seems to have come back – but even worse!
This time, my wifi connection was dropping every time I finished a browser ‘session’ and then moved onto do something else – in another application. When returning to the browser, it had then lost wifi connection. Looks like Apple forgot to do their Regression Testing!
The issue is being discussed on Apple Support forum: https://discussions.apple.com/thread/4141882?tstart=0
Initially, applying the fix below did work, but then I found my wifi connection was dropping again. Nice one Apple!
Fix / Temporary Fix :-
– System Prefs / Network / then Turn WiFi off
– Press Advanced button, it will probably show your usual WiFi network in Preferred Networks list
– Delete your usual WiFi network in this list (make sure you have your connection details/password first!!!)
– Press OK and will then need your System password to ok the change
– You then need to setup your WiFi connection again – I did this via Preferred Networks and ‘Choose a Network’ button, selecting my WiFi connection. You’ll probably then need to enter your WiFi password again.