These two pages really helped me:
Howto Install 32 bit Firefox with Flash w/sound and Java for AMD64
TGHC / 64bit browser with java and flash plugins for Ubuntu
The script worked very well for me. As far as I can tell, everything seems to be working. I am using Swiftweasel and I am liking it. I had already installed some extensions such as Google’s toolbar, and I did not have to reinstall them for Swiftweasel.
gracias