So I updated the bug report over at http://libiphone.lighthouseapp.com
I've had no response to that so I had a look at Ubuntu 12.04. I ran it 'live' off USB on the same laptop and it immediately recognized and mounted the iphone, giving me access to photos etc. I have since tried again to get the iphone recognized in Knoppix but to no avail.
I prefer to use Knoppix over Ubuntu - I find it considerably faster in virtually all respects and the Ice Weasel browser is significantly quicker than Firefox on Ubuntu, even with the same adblock settings etc. Ubuntu also crashes my laptop on virtually every session - the screen renders some very odd artifacts and then freezes, the only way out is to switch the machine off.
I'm considering doing a package comparison vis Synaptic so I can check what packages Ubuntu is running that enable the iphone, and then load said packages into Knoppix. Is it as simple as this or am I going to run into trouble with kernel conflicts/differences that make this plan unworkable?