I'm not sure if this is a known bug or not. However I figured it'd bring it to the attention of the Devs.
Pretty self explanatory, I noticed it when I was using the equipable crowbar and returning it to the magic bag from being equipped.
If you do this instead of applying a weight reduction it makes it weightless.
I recreated it with screenshots in this
imgur album I'm fairly confident that this would be impossible to correct, however I'm not very familiar with the nwn system.
