user accounts and permissions on media drive with FCP 7

I’m setting up some Imacs with FCP 7 and G-raids for media drives. I am having trouble getting permissions to apply for user accounts on the G-raids.

I posted on the OS X forum

http://forums.creativecow.net/readpost/71/862919

but did not resolve the problem.

So question: if no one can solve the above problem of OS X ignoring user permissions on the external drive, will using password protected sparse images of each media folder for each user work as well on FCP 7 as has been suggested for FCP X?

MacPro4,1 2.66GHz 8 core 12gigs of ram. GPU: Nvidia Geoforce GT120 with Vram 512. OS X 10.6.x; Camcorders: Panasonic AG-HPX170, Sony Z7U, Canon HV30/40, Sony vx2000/PD170; FCP 6 certified; write professionally for a variety of media; teach video production in L.A.

Why would ignoring permissions help me to set permissions on the raid? My purpose here is to have each user have a private folder of media that can't be viewed or trashed or changed by other users. So for example I want user 1 to have their own private folder. The admin however would have full read and write privileges.

MacPro4,1 2.66GHz 8 core 12gigs of ram. GPU: Nvidia Geoforce GT120 with Vram 512. OS X 10.6.x; Camcorders: Panasonic AG-HPX170, Sony Z7U, Canon HV30/40, Sony vx2000/PD170; FCP 6 certified; write professionally for a variety of media; teach video production in L.A.