Every month I go to Verizonwireless to pay my cell-phone bill using the current version of Firefox under XP. Now recently I got mad at one credit card company because they started charging me a fee, so I switched to another card. Everything seems fine, I put in all the credit card info and I tell it to not save the info. Now auto fill tries to put in the data which I override, but when I press the button to PAY, it tells me the card security code is wrong. Well I overrode it!

The issue is, even though I type in the card security code over the stuff that gets autofilled, it doesn't override the default value.