So I'm trying to sell two steam gifts for games, the bundles being Half Life 2 (containing Half-Life 2, Half-Life 2: Lost Coast), and Half Life 2 Episode 1 (containing Half-Life 2: Deathmatch, Half-Life 2: Lost Coast, Half-Life Deathmatch: Source, Half-Life 2: Episode One). Is there a reason that it says my backpack does not have any tradeable items? I made sure that gifts are public, and I do not know what else to do.