After a lot of trials, I got it.
Just delete the “wp-content/uploads” and keep the field empty.
Then it is using the default, that is just the same.
That´s strange, isn´t it ?
Seems that changing any php-files or setup new folders is the workaround, but after updating probably the problem will occur again.
Who has the right solution. I agree, that it could be to do with the php-configuration of the WAMP.
I have seen a lot of paths with user Pxxxx. Seems that they use the same provider.
I have the same probleme with http://www.weber-led.de and my hoster is ready2host using CYCONF.
On an other webspaceprovider with CONFIX it works with my other webadresse. http://www.pyramid-projects.com
I guess it is the PHP-Configuration of the interpreter. But cannot influence it.
Hope for solution soon.