I think I have the same appetite for using Synaptic or even apt with the LiveCD.
I just never quite noticed that mine doesn't work with the LiveCD, even though its
right there on the menu. Mine fails somewhere along the way of resolving
sources and/or having 'sufficient memory'.

I suspect it is not expected to work in Live mode, but I didn't know that.
If so, a synaptic warning screen might be in order to educate those naifs
such as I. Especially so, considering Knoppix is usually thought of as a
LiveCD and not necessarily or even usually as a means of achieving an
installed system.