Yesterday... I mean, early today, I found a problem on the "cooldown" of the Skyscale Collection, that instantly ended "Wait for Gorrik".
It happened like this:
I just had finished the "Troublesome Skyscales" Collection with my Sylvari deadeye and the cooldown appeared. Without leaving the Sun's Refuge instance I returned to the character selection screen and loaded my human scourge. Once the Lion's Arc map finished to load I received Gorrik's mail asking to return to Sun's Refuge and so I was able to start the "Riding Skyscales" collection. I thought it wouldn't work, but I was able the start the saddle collection (even already bought the first item).
I just didn't continued because my computer frozen for some reason(minutes after I buy the first item for the saddle, probably a coincidence) and was late night.