Some glitches in inventory in the Pipboy.

I was overloaded, and couldn't for the life of me work out why. So eventually, after dropping stuff one-by-one, I dropped a Legionary helmet. Instead of it going out of my inventory, it changed to Legion Helmet (6), and I went on to drop another 6.

Similarly, I had 3 throwing spears. Or so I thought.

Throwing Spears (3)

so I dropped those, and then it changed to

Throwing Spears (17)

so I went on to drop a further 17 throwing spears. Then I wasn't overloaded anymore.

This doesn't happen on every item I pick up. But certain items. And this is a NV bug, because I can't remember the inventory counts being wierd in FO3.

Thanks all

I've had this happen as well. With a 9mm pistol as well as the spears and helmet.

Find a container and drop everything into it. Even all the equiped items. Then put back one at a time what you want. See if that clears the issue from happening. There have been a few updates and it could be that with all that weirdities like this might crop up. You might have had a scripted item in the inventory.