>A user is not getting the same font as defined in the stylesheet when using Firefox.
>
>The style is very simple:
>
>font-family: Arial, Helvetica, sans-serif;
>
>This font is, or should be, installed on the user PC.
>
>Is there an overwrite in Firefox that would allow a user to bypass the stylesheet settings?

IIRC a user can override font style in Firefox by creating their own 'userContent.css' file.
At the end of the day all browsers are capable of overriding site settings if they so wish.........

>
>Or, what else could be a factor here?