Well, I cannot find Owain. I know where Aulay is but cannot find previous mage.
And, BTW, where Taffic exactly in Trademeet?

If I am remembering correctly he is the one upstairs in the Gallery.

It seems me too but tgere ia only Vashon... May be I need to do his quest and then Owain is appear?

Owain is definitely suppose to appear in the gallery, he is the last person you see to finish all the enhancements for the ROM.

You are probably right about doing Vashon's test because unless you do he will stay there and that is probably why Owain does not come because if he is caught helping with the ring he would be in trouble.

I never ran into this problem because I did Vashon's test before I got that far on the ring quest.

Owain last? Not Aulay?

I hope I got them right. This is the order I did them and all went well for me.
1. Genevera
2. Aulay
3. Owain

Edit
I also found that Lhillias --> Genevra --> Owain --> Aulay is suppose to work. So I now will have to go back and try to see which is right. It will take several hours to get to that point.

Edit
Ok, tested it once more in my game the sequence is Lhillias --> Genevra --> Aulay --> Owain. I did not do any of the quest to get the Senior Mages out of the rooms and each appeared where they were suppose to so I would say go find Aulay then go back for Owain.

Thank you very much, Golden Thief!