Firefox versions normally use individual profiles for each version, otherwise problems will arise. In fact if you are testing you may even use multiple profiles for each version. I use multiple versions but know nothing about virtual machines. Is it not possible to first of all install multiple versions each with their own profile before packaging them? * http://kb.mozillazine.org/Using_multiple_profiles_-_Firefox * http://kb.mozillazine.org/Testing_pre-release_versions#Installing_multiple_versions

Do you keep old settings or is a new profile created on each startup? Can you start Firefox with the Profile Manager? *http://kb.mozillazine.org/Profile_Manager *https://support.mozilla.org/kb/Managing+profiles