disable Creation of submounts

Hi,

I try to install the afs-client to distribute on my terminalservers. On the terminalserver there are different users, which want to create drives to there homedirectory. The client generates for everyuser an submount. The first user who creates "home" as a submount wins, all other users get error messages and have to use different submounts. Also you can see all this submounts under \\afs\... Is it possible to disable the creation of submounts? 

We discovered a problem with USB-sticks and windows. A user maps an afs-drive to the first available drive-letter. If he now puts an usb-stick in the computer, windows maps the USB-stick to the same drive-letter and he can not access the USB-stick. The user have to change manually the driveletter of the USB-stick or change the afs-drive-letter. 

Greetings
Thomas