When using the submit= call in a plugin and you're passing values to the web form, do you use the web form field's name= or id= portion?
Web form fields
Plug-in Code
values=dict(successRedirect = "https://secure.mlb.c...wizard&c_id=mlb",
emailAddress = Prefs['mlb_user'],
password = Prefs['mlb_pass'],
submit="Login"
)