Its not really a glitch, its a limitation of the engine. And the fact is your the only one who has controll over your inventory, and yes this Thread might help you out, the fact remains people will do this and it will not be malicious.
And I can assure you as a full time merchant, I have been there, you dont need to fill your inventory to have a good stock, I would say that is a sign your buying to much, and not selling enough. And need to think of what your taking in compared to what your sending out.