From Rosie's blog:
I have to say, I'm quite frustrated with trying to get cross compatibility with IE and Firefox running my mini-project...Anyhow, I am asking for help at this point, because I'm so frustrated!...
Rosie,
I haven't had a chance to look real deep at your examples, but the quick glance at your text-utils.js reminds of the similar experience that I had that turned out to be due to differences in how IE and FF handle namespace.
Please look at my blog posting where I described my work around. In my posting, look for the "gml:" as a guide for where to place your "aws:" ns prefix. Hope this is helpful.