JFB gives a few errors

Great to hear it worked. No clue what happened, but it could have even been something on Facebook's end thinking something was wrong with you logging in on that PC at that time. It will hopefully clear up there tomorrow. If it's a brand new app for Facebook, sometimes they can be a little wonky over the first 24-48 hours as well, but who knows

As for social integration, yeah, probably best to start a new thread since you haven't already asked and I don't know what you're looking for.. it also helps keep the forum cleaner if each topic is pretty specific. As a quick sidenote though, a user just asked about how to integrate some social stuff into Virtuemart (and other 3rd party extensions) so I gave a pretty generic answer in that thread. Feel free to read it over, and create a new topic if you have more specific questions:
www.sourcecoast.com/forums/topic?id=2393&p=1#p11260

Best of luck to you and your site, and thanks for subscribing!
Alex

No, agree, that's not good or right.. and not something we've ever heard of. You're sure the user's not my account, right? Also, can you check the Joomla user manager and see who's currently logged in when you try to log in via Facebook? That will help narrow things down if there's a syncing issue between Joomla and Virtuemart. From Facebook's perspective though, it's not possible to get someone else's information without their permission. Facebook has huge privacy checks and other mechanisms to make sure that when you authorize an application, we can only see your data.