Proftpd file permissions with mysql auth

Hi,

I think that someone encountered that problem already, I hope.
I am running Proftp 1.2.8 with mod_sql user auth.

Everything works fine. I can login upload and download. I jailed every
user (just mysql user, no unix accounts) in his homedir which I
specified in the mysql table. No anonymous login.

My problem is, how can I set the user and group (as well as
permissions) when uploading? My login fails if I change the homedir
permission to 'o-r'.
Any suggestions welcomed.
Greets
Markus