Jacwiecz - my grand daughter
I claim title of Bresty, so that I can take it to create the Duchy of Turov, which by the way does not own the province of Turov, but I digress.
I attempt to vassalize the Count of Bresty as my armies march on his lands.
BOOM, I wasted all those fine points and he agrees to be my vassal.
I try to create title, but I only have 74 gp, I wait 2 months. I have 103 gp, I hit create title.
I am now Prince of Turov and Plotsk. So, our friend either did not have the 66% or he did not have cash to create the title. But there is no bug, I have just tested it, 2 minutes before I started this post.
More than likely, our friend had 3/5 provinces for a title. Unfortunately, that only means that he had 60%, a lot of people are not doing the math or forget that creating titles costs cash, which is why I think they post it here. I have heard that for Kingdom titles it might require 75%, but I have yet to test that theory.
I will let you all know after I conquer the rest of Lithuania. But I have to wait until the Byz Emperor dies first, seems that I purely by accident, asked the Emperor to make me his vassal. So, I plan to be the next Chief of the Greeks, with a name like Rurikovich, hehe.

Considering making it an AAR. What does everyone think. A Russian Prince on the Throne of Byzantium.