Thanks Dani. I use firebug as well but didn't think to use it for this.
I will regenerate my code in the morning and see if that corrects anything. I had made minor tweaks to the javascript code to use mouseover rather than click and a few other things (scaling, etc).
Giving the "google_javascript" folder write permissions to the user won't change the ability of the code in that folder to write to the cache folder.