Room to the left (end) as you face Xander cannot be rested in.

Fixed.

I'd like to elaborate on this a bit. You can determine whether you're in the "resting region" of an inn by examining the messages that the rest system gives you when you try to rest there. "You can't rest here" means that the region that you're in isn't marked for resting. "You don't have permission to rest here" means that the region that you're in is marked for resting, but you haven't paid to rest there. You can use this to determine where the "resting region" for particular inn rooms is.

Due to NWN's simplistic handling of "regions" in general, it's quite possible that a resting region could appear to cover an entire room in the toolset, but not actually register as covering it in-game (as the Rock Bottom region did.) This is likely the cause of all of the current "I can't rest in this room" bugs. So, when reporting these in the future, if you can move around a bit and try to find places in the room where you can rest (such as the north side of the room you mentioned) or anything else that would indicate where the resting region isn't covering, that would be excellent.