Problem with the config page after installation

[metal-sphere.com]

Hello
I just installed copermine 1.3.5 on my webspace (host : online.net they have linux/apache/mysql server) and I have a strange problems on some pages like on the config page. I can't save the new configuration because when I do that I have this error message (see the screenshot)

(https://coppermine-gallery.com/forum/proxy.php?request=http%3A%2F%2Fwww.metal-sphere.com%2Fpbcopermine.gif&hash=b4ce08a3a75761081a38286b9ad4650870c71bcb)

And the strange thing is when you type the url http://photosconcerts.metal-sphere.com/config.php the page is ok but I don't know why it's the url http://photosconcerts.metal-sphere.com/photosconcerts.metal-sphere.comconfig.php who is launched when I push the "save new configuration" button and not the good url http://photosconcerts.metal-sphere.com/config.php

I made tests & install to another directory & the problem still the same why copermine launch not the good url because I never had this problem before when I installed some similar galleries to copermine.

Thanks for your help because I currently not use the config page & install theme...

[Nibbler]

http://coppermine-gallery.com/forum/index.php?topic=18079.msg83694#msg83694

[metal-sphere.com]

I try your stuff and it seems to work well Thanks a lot for your quick answer