Why i cant change my Ashen Band ring?

I changed my ring once (this is my first time to change ring, in worst case second), but now i can not change it again. Have req. money, exalted rep. etc. On wowwiki say quest is repeatable, but when speak with Aronen and try to click on continue nothing happens. I try reload, relog, but nothing help. Anyone expiriance same problem? Any advice?
Sry on bad english, i use google translate.

Make in-game ticket and you will receive help.

It's a common problem. I've had it happen to me, then after a while the NPC gets activated all of a sudden. Not sure what triggers it.

Just had same problem - my solution was to cancel the trade quest and retake the quest - then i could choose the right ring :)