[mod_python] req.form question

A point of curiosity.  Please don't hurt me.

Some time ago, I was able to refer to a form field value in this manner:

req.form["fieldname"]

Now, I have to refer to the value in this fashion:

req.form["fieldname"][0]

Granted, it's been a while since I've done any new scripting with
mod_python.  I've searched the mailing list and looked at the docs for
both v2 and v3 but can't find any reference to a change in the form
attribute of the request object.

When did the keys for req.form change to a list?

Thanks,
-Chuck