Do you allow a Headband of Intellect to grant additional skill points?
Headband of Intellect: This device is a light cord with a small gem set so that it rests upon the forehead of the wearer. The headband adds to the wearer’s Intelligence score in the form of an enhancement bonus of +2, +4, or +6. This enhancement bonus does not earn the wearer extra skill points when a new level is attained; use the unenhanced Intelligence bonus to determine skill points.
If not, why would you allow it to meet a feat prerequisite?
If so, do you record which skill ranks it was applicable to if it is lost, destroyed, or stolen?
The FAQ does not talk about feats, but it does state that you can gain bonus spells as long as you slept with the item. But, you also lose the extra spells (uncast ones first) if you no longer are wearing the item (or it is destroyed).
The DMG implies (in the tables) that if your Int goes up, you retroactively get extra skill points for earlier levels AND you get extra skill points for a headband of intellect. This disagrees with the description of a Headband of Intellect. So, if they made an error here with the headband, did they also make an error with the retroactive skill points?
So, the intent of WotC is not totally clear.
However, I think that like skill points, feats are permanent unique abilities that other creatures might not have. In other words, when your Strength goes from 13 to 14, the bonuses you gain are the exact same ones as when any other creature's Strength goes from 13 to 14.
Skill points and feats are unique to each creature. A creature could take the same as you, but usually not. So just like skill points, feat prerequisites should not be gained via items. IMO.