The logout form is showing up as follows in the code:
<form action="http://oshow.com/" method="post" id="sclogin-form">
Obviously, that's the non-https link to your site. I'm not sure why that's the case though, if you have the Encrypt Login Form setting enabled.
We're trying to determine the cause, but are unable to do so yet. Can you try enabling the standard Joomla mod_login form on your site and see if you have the same issues that you have with the SCLogin module? Our SCLogin module is based off the code from the mod_login module, with some obvious tweaks. The login and logout code is almost identical though, so I'm unsure why you'd have a problem with ours.. unless it's also happening in the standard login module.
Let me know your results as it will really help us narrow things down.
Thanks,
Alex