There was a bug at least on the NFPS server side of things where the T1 was bypassing the Username/Password field.
I've heard that bug has been patched. Which might explain why everyone is getting the request to re-enter there username/password because it was already "logged in".
On the MAG with Stalker Middleware 5 under account all you have is "Log Out" where as on version 4, you had 2 different options.
The other thing I heard today is that there is a "ISP lock" in place, Im currently trying to get more information on this.
Lots of work being done on the backend these days.
Edit: It's been confirmed to me that it is an ISP lock only, and not IP Address locked. The example being if you have comcast, and you go on any other comcast you are good, but if you go from comcast to verizon you will need to perform an IPTV Reset.