lost username/password when I updated
When I updated to Firefox 4, all the usernames and passwords that were saved on the last version did not stay "remembered". Anyway, I can get them back?
Wšykne wótegrona (1)
Do you mean names and passwords in the Password Manager or do you mean that you are no longer logged on to (remembered by) websites after closing and restarting Firefox?
If the latter happens then you have a problem with cookies that are not kept or are corrupted or the file that stores the cookies is corrupted.
If Firefox doesn't offer to store passwords in the Password Manager then check that you aren't running Firefox in Private Browsing - Use Firefox without saving history mode.