Firefox don't save changing

good morning. please, i have downloaded firefox portable 3 beta 5 and it don't save changing. The home page is always welcome to firefox 3 beta 5 and if i entry new home page, at next restart it return to default. same for location downloaded files: it always return to "desktop" at next restart. Same to ask if i want last session: i ask that don't want ask never but it always is so. what is this problem?
Is important to say that this problems are even in version 2.0.0.13 not beta. is a my problem? how can i solve? thanks