There is a bug where you can't trade if the character is being buffed or something happens to it even in town, also you can't trade with it if that char has a pet summoned.
Sorry if this was already posted ..if it was...just ignore it
Also 1 question..cubic from summoner shouldn't go to the enemy when the summoner's pet is attacking?..i mean that is the skills for the attack that a summoner has.(if it is true... then cubic do not work)