very good work you are doing in this site
sorry for the english that follows...
i am doing a work making cds for distribution in valencia (spain) for small city councils on the area. the info is on html for it to be able to run in GNU-LINUX, mac and windows. i found this opportunity a good way to make diffusion of firefox and your version on portable is the perfect solution. but i find that your solution is thinked for a person that changes of computer and i see also other way that you may think also: about the cds that are for distribution (in different computers but several times in the same). i mean, that it would be a good idea to give the choice of no deleting the preferences, so each time the person uses the cd doesnt need to say ok to the window with the warning message.
also... i dont know how to transllate the warning windows to spanish. since i am in an spanish speaking country, that a user had the first contatct with firefox in english will do that he/she will cancel since they wouldnt know what it means. i think i have to compile but i dont know. i translated it on the source but it doesnt go in the cd: the english message goes on :D. If you want i can give to you the transllation (i understand english better than i write :P).
i will try that my client (fun of freesoftware) waits for a week (i am supossed to give the work tomorrow or what i found) to see if i find a solution since i think it is a good way to go into people that doesnt know about freesoftware (and now i have the oportunity), dont you think?
thanks a lot for developing