I have Weapon Mastery 1 and when I reached level 11 I went to the NPC Belkis at the Kamael village to learn my new skills.
Initially the list half-showed the Weapon Mastery level 2. I scrolled down to see what else was there and then the window refused to show the Weapon Mastery skill again.
I tried learning the Armor Mastery skill, in the hopes of Weapon Master showing again. The scrollbar indeed vanished but still no Weapon Mastery.
Cool... I played casually for two hours and I found two bugs (plus of course what others have posted). Time to return to my main, maybe they will fix it in CT2.
Nice job.