Firefox had saved my login name and password for a site, when I changed the password, FF won't ask to save/update it so I have to enter it manually now. How do I get it to prompt me in FF7.01?

Question

Using FF7.01 on a HP Pavilion dv6775us laptop running Vista Home (updated continuously)
The site owner changed the rules in order to improve password security so I was required to create a new password. When I did so I was not prompted by FF7.01 to save the new password.
When I next logged into the site, FF remembered the user name but presented the old (invalid) password. I was forced to manually enter the new password, but again was not prompted to save it to FF.
I then went into FF Security, viewed the saved passwords and deleted the entry for the site in question. I expected that when I logged into that site the next time I would be asked if I wanted to save the username and password. I wasn't.
I then exited from FF and relaunched it and again logged into the site in question. I was not prompted to save the username or password.
How do I force FF to ask for and then save the username and password?

Answer 1

Thank you for your reply.
My problem isn't removing my log-in name and password for a site.
The problem is I already had the log-in name and password saved by FF, but I was required by the site to change the password. FF did not recognize that it had changed and refuses to prompt me to save the new password.
After several attempts to force the prompt, I deleted the site from the Saved Password list, hoping that the next time I entered my log-in name and password on that site FF would ask if I wanted to save both. That did not happen even after exiting FF and relaunching it.
So, right now FF will not save my log-in name and password for a site that it used track for me. Given the complexity of the new password, I really do not want to manually enter it every time I use the site.
Regards.