Thanks heaps for this info mate.
The air-con isn't performing as well as it did before the radiator was replaced so I'd dare say the bleed wasn't opened up. Mind you it was also 40c
The stereo presets are gone but the important part was saved. All the crossover values, time alignment and eq settings for my audio system are all still there. I'm running everything active, it took me months to get the tune right!
I'll attempt the reset tomorrow but I seem to have trouble with the timing of the whole procedure.