ang mozilla firefox ... is a open source... meaning open sa tanan.
so naay possibilities na ma HACK imong account number, profile, etc. if your paying it online. usa sa mga disadvantages kani na browser.
ang disadvantages - pwede ma delete dayon ang mga cookies, internet temp files, accounts profiles (example sa youtube, friendster, yahoomail, gmail etc. that requires username and passwords)
ang imong complain is ... dili mo save ang imong username and password?
there are some steps
1. click mozilla icon
2. Goto "Tools"
3. click "Options"
4. under options tab bar click "Privacy"
5. under privacy cookies un-check the box "accept cookies from sites"
6. under privacy private data un-check the two box's "Always clear my private data when I close Firefox" & "Ask me before clearing private data"
7. click "ok" button
mao na ang pama-agi pagsave sa imong username / passwords everytime you enter some websites like youtube, friendster, gmail, etc.
p.s. try yung mozilla 2.0.0.2 ( mas ok na kaysa mozilla 1.0.0.5
www.firefox.com