User cannot create/delete directory within its root folder

I'm using WebFM with different roots associated to different roles.

Unfortunately a user cannot create directory without "administer webfm" rights.
If I give "administer webfm" to a roles the related users can access every roots and also create/destroy folders within. This is very pity for security...

Can anyone help me? Is there any version eitehr available or planned which solve this bug?

Mario