Fallout: New Vegas Message Board  

You only need to have option 5 (unlimited ammo) turned off as it is that option that is causing the problem.

Also, it's not hopeless if you forget to turn it off before they take your stuff as you can just turn it off while the game is stuck.
I did this when I was first going in to see Gloria Van Graff and the only result was that I ended up with 16 million of some ammo type (don't remember which it was).
Later I decided to drop it on the ground so as to not have it cause problems in the future, but then it turned into a negative amount (don't remember exact number).
I don't want to mess with that pile...

If you dont wanna turn the option off or if you like myself have a huuuuge list of guns and butter you can deposit them all in the trash can in front of the tops and they will remain undisturbed. Or for the silver rush put them in the dumpster beside the building. Plus if you do the van graff missions they wont have you hand over your weapons anymore.