Well, it seems I've figured this out for myself. It turns out EndNote can only import from other EndNote Libraries and Plain Text Files. Thing is, you can only select these two things in the Open dialog. They must also be defined by the TYPE code and not .txt (which, I suppose is the way it should be, but it could at least recognise file extensions.
Anyway, Chimera (my default browser) and Omniweb don't add this info when saving a file from these websites. IE will do it, but I hate that browser.
The solution? Change the file type using aaw.mo.free.X to TEXT and all is well, as long as you've saved in the right format and select the right import filter.
So, thats that then. I should be less hasty in posting problems. Sorry to have wasted everyones time. Please feel free to delete this thread.
biscuit