Nice game!
It was a pretty nice game, i liked it quite, it was nice gameplay and such.
And i found the solution to load not working!
It has nothing to do with firefox, but with settings!
Right click anytime, choose settings click on the folder icon with a green arrow, and take the slider all to the right, then it says "allow ungrounded.net unlimited" and then your savegame works!
Woot i rescued my main file!