I installed WPG2 and a new install of Gallery, and fell in love with your plugin, however I soon encountered a bizarre problem.
I had created links in WP to point to Pages in WP. Clicking on the link to go to a Page, instead, loaded Gallery directly, not embedded inside WP.
Checking the address bar, it said I was viewing the Page I had linked to, but it was loading stand alone gallery.
Going back to the Link- hovering over it, the correct page url is shown, but it sends the browser to Gallery.
This only happened to two links out of the 26 I had created, so it wasn't a global thing, which made tracking down the problem crazy.
I spent a few days trying to resolve this, and once I disabled this plugin, everything worked as it should.
I wish I could provide more information to track this down, but this is as much as I have to offer.