Did you check the setting?

• Tools > Options > Security: Passwords: "Remember passwords for sites"

• Make sure that you not run Firefox in (permanent) Private Browsing - Use Firefox without saving history mode

• You enter Private Browsing mode if you select: Tools > Options > Privacy > History: Firefox will: "Never Remember History"
• To see all History settings, choose: Tools > Options > Privacy, choose the setting Firefox will: Use custom settings for history
• Uncheck: [ ] "Automatically start Firefox in a private browsing session"

every day i opening irctc.co.in. very very slow unvisitable error

what do to do

tell me

There's a setting in IRCTC web site (autocomplete =off) which prevents Firefox from saving passwords. But there's a workaround.

Using a bookmarklet

1. Bookmark the "remember passwords" link on this page.
2. Go to the log in page of the site you want to save your details.
3. Enter your login and password, but do not submit.
4. Open the bookmark you just made. (Nothing will appear to happen).
5. Submit.

http://kb.mozillazine.org/User_name_and_password_not_remembered