Certain items, in particular ones which have stat modifiers, are not correctly identifying when you find them. At least the following ones are problematic:

Amulet of the cold heart
Amulet of perseverance
Amulet of defense
Amulet of protection
Necklace of the silver tongue
Bracers of protection

I have in my current game found and ID'd all of these, but when I find new ones on the ground, they show their unidentified format (gray amulet, bronze amulet, platinum amulet, silver amulet, shining necklace etc) every time. Shouldn't they be showing what they are?

I suppose the issue here is the stat modifiers. They should presumably not be visible when you find a new one, but surely the item on the ground should be "Amulet of perseverance" instead of "bronze amulet" if it's already been successfully identified? And then after wearing or re-identifying, it would appear as "Amulet of perseverance {Wi+3}.

It's a pretty annoying bug which makes one spend scrolls of identify in vain, just to notice that meh, it wasn't a new amulet after all. (Yes yes I know, there's the list of identified items to circumvent it, but using it is not part of the normal gameplay flow.)

EDIT: Looks like there are also other similar items, which do not contain stat modifiers. At least bracers of regeneration.