We've gotten countless complaints of this on 2k1, and its happened to me too. Sometimes people can't interact with any NPCs by touch (IE: they cant walk through a door, or pick up an item)
The only way we've been able to fix it is by saving all their weapons and strings, then resetting their account, and restoring the strings and weapons. I'm guessing this might be some kind of EXE bug? I hope it gets fixed.
If anyone says "its called lag" I will rip off your fingernails and pour salt in them
It isn't lag.