What I meant was, aiwass, that it's useful not to think about it being in some overriding "key" based on the Ionian mode, but in the key that the mode is. So E phrygian is in the key of E... phrygian. This is of course a completely different key to E major, which is E Ionian.
Iamtheeggman, if you are still confused, it's because I'm not good enough at explaining, don't blame yourself! :o
"Dozens of people spontaneously combust each year, it's just not that widely reported".