i had a similar problem where i got the 'receiving' message, my friend had just been killed by a guy, i killed the guy who killed my friend, tried to pick up all the medical supplies ammo ect... from my dead friend, and i couldn't use them or equipped them, i thought maybe my friends body glitched out so i tried on the guy i just killed, same problem, i think its bug within the game, not to do with your connection, however this is a problem that needs to be looked into, my friend had alot of ammo we needed and lost,