Unable to gift coins that were acquired from selling gold

I had 6 coins on an account, I've sold gold on the marketplace for 25 coins, now I have 31 coins on that account. I tried to gift my coins to another account but I was only able to gift 6 coins even though I have 31. Are coins acquired from selling gold not giftable? If so, then why isn't it stated on the coin gifting page among the other information provided there about gifting coins?

The coins gained via gift/trade are "locked coins".
"Locked coins" can be used only on Store and Service
After 72 hours they become "normal coins" usable everywhere. So at that point you will be able to send them to an other account

More info here: http://forum.warmane.com/showthread.php?t=327127