@GeorgeMTO Of course, if you tell Amazon "Look, we've been distributing the first volume for months!", Amazon will take the first volume down while they piss-and-moan about the current one...
Edited to add: You know, if you go to tentai's site, it doesn't show a reference to v2. Yes, you can click on a link to it from outside, but going through the site says that v1 is the latest and greatest.
Edited again: Hmm... Book one is under "romance", book 2 is under "high school", and they aren't linked. Methinks they need some website magic performed.