Yeah, I got the pop-up. I'm in Sierra Madre right now and have done the first three quests. Experience indicator is still on the the far left of the bar.
Edit: It is changing in the Pip-Boy, but it's at 8,000 out of 71,000. That can't be right.
That sounds about right, early on when the game out, (when there was no patches) There was a bug for me when the game stopped adding Xp, and I had to restart my character,
even later in the game when i was about lvl 21 it stopped adding xp and I had to restart again (Before any of the patches)