[SOLVED] Header image in wrong place

Hello,

on my blog I updated manually today from Atahualpa 3.2 to the latest 3.7.10.

It seems that everything works fine except there seems to be an issue with my header image.

As described in the FAQ and as in my previous installation, the header image is stored in:
However, my blog wants to access the image under:
What's up with that?

I manually copied the image in the directory above, so it is shown now, but I want to find out why it is not working as descrebed because I fear, other options might not work that I have not noticed yet.

Any ideas why Atualpa 3.7.1 tries to get the header image from another place as it should?

Thanks in advance,
Robert