After the patch that should remove multiple rune sockets, there was this bug that actually gave a second socket to items that had one. I used the second slot, and after the revert, that slot vanished, without giving me the rune back.

Even though the item doesn't describe the rune bonus, it's still there, as we can see on the following pictures (look at the critical chance. It register the bonuses of a small flame rune - 3% crit chance):

[Linked Image]

[Linked Image]