Hey Danno,
I just thought of something! (yes, be afraid!!)
When I am in auctiva, on the lister page, creating a listing, the page always loads funky for me...little things, comes up slowly...click on one thing, like skip to shipping section, and the page jumps to a different area...click save, jumps back up to the pic area...really annoying crap!
I wonder if it is because I am using IE? I've never used any other browser. But I do recall that when I mentioned it my former asst, who uses firefox, she said she didn't have those issues!
Is this what you mean by Firefox being more script loading friendly???