embedded wpg2 no images, gallery2 itself is ok

Since today, I can't view my images anymore in the embedded wpg2 pages, while I got like 120 images in Gallery2 which I can see when I browse directly to it.

I first noticed after I wanted to add some newly added pictures to a new wordpress post. When I pressed the wpg2 button in the editor, the imagechooser pops up, showing my album tree (so far so good). But when I click one of the albums, none of the images in it shows up in neither IE7 or Firefox 3.

When I go to the embedded gallery2 page (http://sonnega.eu/flightlog/wpg2), none of the albums are shown, the page is just empty besides the header. The gallery2 page itself shows the correct images (http://www.sonnega.eu/fotoalbum/main.php).

It worked a couple of days ago, and as far as I know, I did not change anything on the server. I re-activated the plugin, revalidate it, and everything looks ok, it just doesnt work, no images at all.

Can you guys give me a push in the right direction where to look?