All,
thanks for the links to the other websites Ken, there has certainly been some major changes in parts of the spectra.
Regarding the differences between Jeff's spectra and mine, perhaps it's the skyglow I image through in suburban Wollongong compared to Coonabarabran! Overall, they are very similar in shape and the size of the responses.
Comparing the spectra from the website and my resolution (11A/px), the changes he shows from 4660 to 4720 A, cover 5 pixels on my ccd.
If the sky clears tonight, I might try with the unmodded 350D, as I can get down to 2.5A/px with 135mm lens + 2x teleconverter.
cheers
Mark