Netstorage WebDav - Can only see and create folders


I am attempting to map a Netstorage drive using WebDav from Windows 7 32bit or 64bit or Windows 8.1 64 bit. I have read other posts where people have had problems, but I think my problem is a bit different. After mapping the drive, I am only able to see folders and create folders. Creating other files results in error 65535. Copying files to a folder, from by harddrive, results in "Can't read file from the source file or disk".

I have another customer, with almost the same setup. Both Netstorage v. 2.0, same Apache version aswell. And it works in their environment.

If I log in via the webinterface, everything works file. It is only when I map it in Windows. Some say this is a bug in Windows and I have installed all the updates Microsoft has released regarding WebDav. Again, it works in one environment, but no the other.

It looks like rights of the user, but since it does work over the webinterface, it can't be.

Any ideas?

Thanks in advance,