Jan,
I tried it and I think I am VERY close to integrating all three. Here's what I did.
First I installed Postnuke.
http://www.postnuke.comThen I installed the phpbb 2 postnuke module
http://phpbb2pnmod.sourceforge.net/index.phpGot those to work fine then I did a fresh install of 4images and the integration to phpbb mod.
IT WORKS!!! well sort of. A few bugs that I don't think are major but unfortunately I am not a PHP'er.
For it to work you need to log into to POSTNUKE first. For testing use login: tester1 password: 123456
As you can see it logs you in to postnuke but if you go to paparazzi pics (upper right block) it takes you in to 4images but you are not logged in.
BUT... if you go into the phpbb forum first then go back to the paparazzi pics it has logged you in!!! yay!
So that's my first problem and also I have noticed that it gives an error if you try to log out from 4images. This could be solved by eliminating the log in / log out feature in 4images since postnuke should be the one controlling the log in / out.
Ideally I would like to have postnuke user table as the primary user table.
I hope you can help out because that would be VERY cool to get all three working.