The Mini supports mirroring as i bought it May 2012 and its the mid 2011 model so let concentrate on that one for now. MBP probably not but i Share Screen onto Mini from it so i dont need it to, only need the Mini to mirror.
OSX is 10.8.WhateverWasUpToDateYesterday
The mirroring tools, symbols and icons all appear so its capable, turned on, and willing, its when i perform a mirror from this mini, the warped imaging appears.
i dont know if i have arouter issue as i have 2 routers on the same network. That all works fine with wifi, DCHP address, etc, so i assume not. I also have a netgear switch between routers and ATVs so dont know if that can cause problems.
It is likely a network issue, you have quite a bit there. The ATV and Airplay device need to be on the same network completely, if mine picks up the modem and not the router that the ATV is etherneted into I lose Airplay. It could also be interference from too much on the channels, something like iStumbler would tell you more. I don't know enough to look at your set up blind I'm afraid but check the network is the same and do the iStumber check and change channels if necessary and you can. As you get some picture I am guessing interference this could also come from another electrical device.
taking your point in order Jules:
ATV, both of them, are on the same network, tried wired and wireless.I have one network, but 2 routers, but only one hands out IP addresses. Although this sounds complex and could be a problem i dont think it is as the network is set up as everyone recommends with 2 routers and everything else works, iOS mirroring works. Definitely on the same network as there is no other network, and the sound works but visuals are blurred.
what do you mean by 'modem not router'. whats the difference? i have a Linksys WAG200G receiving the broadband into the property. thats a Router isnt it? Routers are the modem arent they?
looking at istumbler now but logging on remotely it doesnt appear to be finding any networks at my house, when there is... may be me as only had it 5 mins...
cant change the channels as i have one router on 1 channel and the second, which is Cat 6 wired to the first, is on another channel, just as recommended