Well the weapon image in the inventory is the same as a +1 weapon, the weapon is +3 for a day then the weapon is destroyed,
Try the special abilitys button, since you can chose what type of weapon do you what.
"He who fights with monsters should look to it that he himself does not became a monster... when you gaze long into the abyss the abyss gazes into you..."
- Waterdeep city constrution.
- Shadowdale low level adventure module.
- Rashmare /Thay high level adventure module.