Will check that about the anonymous role. I am wondering though.. could it be that this happens because we didnt convert the databases btw. 3.6.1 and 3.7.2 ? Indeed there are some changes between the databases, and I'll try that as well.
It is probably because of the permissions update. There was a security issue with earlier versions of 3.6 with related objects (e.g images). Basically eZ publish did not check if you had the rights to see an objected if it was embedded in another one. This was resolved in 3.6.2 if I remember correctly.
Upgrading the databases did nothing. Giving the anonymous user read access to the media files made the error message disappear, but still no images shown in the website..
the site we are working on now: www.naturgassgrenland.no.. a picture is supposed to be shown on the frontpage