Why do hidden fields in forms show up on Firefox?
Why do hidden fields on forms show up on Firefox when viewing a website, but not on Chrome, Explorer or Safari?
URL of affected sites
Alla svar (2)
Todd, you may be having a problem with some extension or plugin that is hindering your Firefox's normal behavior. Have you tried disabling all add-ons (just to check), to see if Firefox goes back to normal?
Maybe a problem with the form fill feature of the Google Toolbar. See http://www.google.com/support/toolbar/bin/answer.py?hl=en&answer=47972 - AutoFill : Web-browsing tools - Toolbar Help
See also Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems