wrong data in table xwiki.doc breaks permissions of space

Situation:

A space was visible to non admin users only if the user has an adminstration right on the table.
If this was missing (only view, comment,edit,delete) the user wasn't able to see the space.

After some investigation I found that in the space where 2 documents, which were deleted some time ago. But this 2 documents were still in the space index. The author wasn't set.

I delete this 2 documents via SQL from the xwiki.doc table.

After this the space becomes visible to normal users.