I realise there have been many wifi issues with Lion reported on this and other sites but mine is perhaps slightly different from most I've been reading about. Basically wifi works fine EXCEPT after a) I shutdown my (2008) imac, b) I restart it or c) put it to sleep. The wireless icon in my menu bar shows an exclaimation mark stating there's no internet acess. I have to switch wifi on and off several times before I can connect to the internet. Once it's actually connected it's fine. If it goes into sleep of its own accord via my energy saver settings it's fine too. My wife's laptop PC, my old G4 imac, my ipod touch and my cellphone can all connect to the net on the same network, no problems there. If I reboot my imac with a clone of Snow Leopard on an external drive that connects straight away too. I use an airport express. Unfortunately it only has one ethernet port so I have to use wifi. I only started using it recently, my old Buffalo router developed a problem and needed replacing. I connected to that via ethernet but occasionally used wireless and there were never any problems with it. Toggling wifi on and off is not the end of the world but it is pretty darn annoying. What is happening that is stopping me connecting to the internet? Little Snitch perhaps? Any ideas from those with similar experiences would be welcomed.