This is getting interesting by the day. I was checking out Sign On Manager for two sites that I commonly used, and the script failed for both. Looks like the number of variations will never cease.
Twitter.com : The submit button for the Login form has an
id = "submit". Because of this, calling the
document.forms.submit() links not to the function, but to the "Submit" Button. The error I get is obvious. Still looking for a way I can get a handle to the form.submit() function prototype.
Reddit.com : The Login form has a
onsubmit=return login(this). The script looks at the onsubmit, sees that it is of
function type, and does a
form.onsubmit.call(). This fails as we have already lost the contest of
this. I am presently working on fixing this, and checking if this just a symptom for a bigger bug.