ncbeeny,
Sorry to hear your having issues with the update process. The v5.1 release did overhaul the installation process quite a bit. Instead of installing/updating each individual module/plugin, you just need to install the main component file from this site. That will automatically detect and install each of the sub-packages and even detect what should and shouldn't be installed. That way, you don't have plugins for Community Builder or JomSocial if you don't have those extensions installed.
You shouldn't need to manually update any individual files anymore. With that said, we are working to improve the Joomla Update Manager area as it can be confusing there still, and I do apologize for that.
For the SCLogin module, I'm not sure what's happening there, but we'd gladly help to investigate. The SCLogin module simply copies the Joomla login functionality over and the login process is actually handled by Joomla itself. If you're seeing an "Invalid Token" error message, it's likely due to a session or caching issue on your site. The following are the things I'd recommend testing to fix it:
* Disable caching in the Joomla Global Configuration area. Test again. If that works, enable caching but disable it in the SCLogin -> Advanced parameters area
* Test with the standard Joomla mod_login module to see if that has the same issue.
Let me know how that goes, and again, sorry for the inconvenience. The install process is being improved though, and your feedback is very welcome.
Thanks,
Alex