I stand corrected. They're only up to episode 18.
As for episode 19's release date, you'd have to ask them by going to their IRC channel... and well, quite frankly, let's just say that fansubbers don't like to give out release dates.. it puts unwelcome pressure on them to meet a deadline.
I mean, sure, we set deadlines for ourselves, but we never meet them really
Like.. the group I'm in.. our sub of episode 2 of Tenchi GXP was supposed to come out over 2 weeks ago.. it just went pre-distro

(Meaning it'll be out for the public within the next couple days heh)
So yeah... deadlines suck. All you can do is wait. (Trust me, I know its hell.. I am waiting on Mahoromatic season 2 episode 7. At least they've been consisent so far and relead one ep per week..

It should be coming soon! )