Well, I'm an idiot. I should've searched more threads before posting.
Turns out that when you're on the main apps page you have to first click the little "A" red button and login BEFORE you click on the app icon. This is after you've already set up the app ID *and* the facebook profile (login/pass).
Hope that helps someone in the same situation,
Hey guys and gals,
I got this sweet Labor Day deal on the 42" 720p plasma and I love it. The Blu-ray player BD-C5500 is great, and I've got it synced to the wifi and have setup the apps account as well as logged into the apps.
But when I go to actually run the apps (like Facebook, Twitter, mostly) they just give me an error message that says I need to create a user account first.
Our Netflix account works find, as well as Pandora, USA Today, weather, etc.
There seemed to be a couple firmware updates the first few times I started up - and Facebook was one of the updates, from what I could tell watching the progress.
Thanks for your help!