Reply to onthepike: I did not post my website as a reference, because I did not have any (I just installed and tested it locally) - that is why I attached a snapshot of the error. And no - the problem was not related to the absence of content (albums, images).
Here are my observations:
I found that the problems with the popping-up ligthbox camera image (see my previous posting) is caused by Drupals "ImageAPI" module. I had created some test content using ImageAPI, ImageCache, ImageCacheUI, Node Gallery, Note Gallery Access and Node Gallery Lightbox 2 Integration. When I had the "camera with a line across" error, I gradually removed all of those modules, but it was not until I removed the ImageAPI module that the error disappeared. I think the error is related rather than to the content I created rather than to the ImageAPI module being enabled, because I can not reproduce the error on a fresh installation of both drupal and cpg ny enabling only the ImageAPI module. I will not follow this any further - this is just to note my observations here should anyone else need them.
Regarding the use of the bridge itself, I have made some progress, but still have problems though.
Without the visualisation-plugin, everything works OK. I can log in to either of the two systems and then go to the other system and then already be logged in with the same credentials/rights. I can view pictures and do everything (at least all of the stuff I have tried) in coppermine.
But when I enable the visualization plugin, I have some problems:
1) I can see all the thumbnails on the cpg front page, but when I click on one of them, I get the following error: "Error You are not allowed to view any images".
2) I sometimes get these warnings:
warning: Missing argument 3 for cpg_die(), called in /home/www/egebjergvej.dk/billeder/displayimage.php on line 38 and defined in /home/www/egebjergvej.dk/billeder/include/functions.inc.php on line 353.
warning: Missing argument 4 for cpg_die(), called in /home/www/egebjergvej.dk/billeder/displayimage.php on line 38 and defined in /home/www/egebjergvej.dk/billeder/include/functions.inc.php on line 353.
These warnings are not a big deal, since (as mehdi wrote in the previous post) they can be configured not to be shown in drupal.
3) When I click on "Admin Tools" from the file menu, then I get the following error: "Critical error There was an error while processing a database query"
4) When I try to click on users (usermgr.php), then there is a blank page only showing the text "Fatal error :".
So suggestions to what could be wrong are very welcome :-)
I have deployed the system on the web now.
Drupal:
http://www.egebjergvej.dk/Drupal version is 6.17
Coppermine:
http://www.egebjergvej.dk/billeder/Coppermine version is 1.5.7(snapshot of svn version 7757 (last night))
User: test/test.
I think there is a huge need for this bridge - I have been searching some time for good drupal image gallery that facilitates a lot of nice stuff like Coppermine, i.e. easy batch upload/creation of albums, but I have only encountered a lot of postings on drupal.org where other guys look for the same as me. And it would just be excellent if cpg could just be used inside drupal instead!