You mis-understand. The tooltip is fine, but the display of the item on the character sheet isn't showing it. My guess is you pulled the info from wowhead in 3.2 and of course had no reason to re-pull it in in 3.2.2.
Check 'Loukno' on "The Venture Co" (US) Resto set. If you hover over the item in the far left the tooltip is pulled and displayed correctly, but wow-heroes is only showing the one socket (and no empty socket).