I've had something really weird and annoying happen today. I went into Gomorrah to talk to Dazzle for the White Wash quest. Offloaded my weapons to ED-E's inventory, told him and Arcade both to wait outside. Went in, talked to Dazzle, all went fine... then I come out and discover that the weapons I gave ED-E- and ONLY the weapons I have ED-E- are missing. The energy weapon that was in ED-E's inventory before he was told to wait outside is still in his inventory.

Is there any way of fixing it without replaying a considerable piece of the game since my last save?

Check out console commands:
http://fallout.wikia.com/wiki/Fallout_3_console_commands#Inventory_manipulation