What's the reason this isn't compatible with the iPhone 4/other devices?
Also, trying to open the preferences (10.6.8) takes 20-30 seconds of beach ball frozen before the window comes up (and 5-10 to close as well, without changing anything)
Because only the iPhone 4S and iPad 2+ support AirPlay Mirroring.
There are ways to do it with apps for jailbroken iOS devices, though you're likely to get a lesser quality. You might want to have a look at this one for example, made by a former colleague: http://www.plutinosoft.com/idemo
Comments
What's the reason this isn't compatible with the iPhone 4/other devices?
Also, trying to open the preferences (10.6.8) takes 20-30 seconds of beach ball frozen before the window comes up (and 5-10 to close as well, without changing anything)
Because only the iPhone 4S and iPad 2+ support AirPlay Mirroring.
There are ways to do it with apps for jailbroken iOS devices, though you're likely to get a lesser quality. You might want to have a look at this one for example, made by a former colleague: http://www.plutinosoft.com/idemo