It seems to just be one of the many irritating invisible barriers that Obsidian saw fit to place absolutely everywhere. If that is the case, there is no bug. However, I'm using this mod to get rid of the invisible walls: http://www.newvegasnexus.com/downloads/file.php?id=35011
That mod is not complete and can induce getting stuck in the unfinished areas.
One of the many problems that we already have enough of in Fallout New Vegas:
http://www.gamesas.com/index.php?/topic/1131087-clipping-borders-and-pathing-issues/page__p__16572956__fromsearch__1entry16572956