A while ago, I asked this question for which no solution was found. I have since re-installed the host in question and gave it to a family member.
So now I will be unable to validate any answers given (if there might be new ones) and the problem was never solved either.
So, should I delete that question?
The reason I am especially torn about this question is that I put some research effort into it which someone else might profit from if he/she experiences the same issue. Then again I don't like to have questions open for which I could never determine a definitive solution.
I voted to close the question. I think the key is that no answer can be validated. Whatever additional information I (or someone else) might have gathered, it isn't even sure if it would have lead towards a solution to the initial issue. So none of the content in the original question is of real value either.