Email already exists - signup not checked

I have LoginToboggan installed, as well as email_registration, with inline_registration. If I enter an EXISTING email address in the node-create form, it is never checked if it exists.

Therefor, user asdf@code.com is originally given the username 'asdf'.
Subsequent asdf@code.com is given 'asdf_2' etc... instead of being told that the user already exists.