Ok, Ive done a fresh installation live now
www.clan-smaka.se/v7. The problem still exists. However, if Im logged out and I dont see the forums where I dont have permissions (since Im logged out) it works perfectly. But when I log in and do the same search in an "open" forum (exactly as I did when logged out) I get the above errors.
Feels as a bug, and probably nothing hard to fix for the creators :)
EDIT:
Be aware that searching All forums, works fine logged out as logged in, even as superadmin. Its when I choose a specific forum to search (as a superadmin) I get the error when logged in.
When I log in as a normal user (have different users with no permissions and not included in any groups) I can search perfectly as well.
And if I add this normal user to a group with certain permissions, I can still use the search function perfectly.
If I also add him as administrator (not superadmin) the search also works perfectly even if I give him all rights.
BUT!! If I delete him from admin and add him as a superadmin, the error occurs.
To make a long story short ;) Normal users, group-members, administrators (even with full permissions) can search when specifying a certain forum. But superadmins cannot search specific forums, only "All forums".