Hey Glen.... I have had Mozilla Firefox for over a year now. Danny :+}
did you ever in the past permit firefox to remember your password and then later on changed the password on the site?
this way firefox is trying to use an old password and doesn't get you logged in.
look in EDIT and choose PREFERENCES
click on SECURITY and then the button SAVED PASSWORDS
this will give you all the sites firefox is familiar with.
click on STEVEGOOD.COM and press SHOW PASSWORDS to compare it with the one you are using.
you could remove the one selected and firefox will ask you again to remember it the next time you will log in.
good luck!