Hmm.... I wonder if the site is glitching out or something.
Try this. When I go to my album I pull the URL and it looks like this:
g6ownersclub.... forum album.php?albumid=XXX
I just pulled out parts of it, the X's are the ID number I assume yours is different.
But when I got to add pictures I get:
g6ownersclub.... forum album.php?do=addpictures&albumid=XXX
So this may be a long shot..... but Pull your URL, and just add "do=addpictures&" after the question mark. Maybe it'll get passed the hang up and get you to the upload screen.