[Samba] files disappearing from Samba server

[Robert Wickberg]

I'm the tech coordinator for a high school.  Last year, we had a file
server kids could save work to that was a generic Celeron 800 PC with an
IDE hard drive.  It ran Debian Sarge, with whatever version of Samba
ships with that.  It was down to a couple of gig of free disk space by
the end of the year, so this year I took an old Compaq Proliant server
(ML360 or something like that) with a three drive RAID 5 SCSI array and
installed Debian Etch on that with whatever version of Samba is shipped
with that.  School's been in session a month now, and I've had dozens of
kids come up to me and claim that they've written files to their mapped
shares (P: maps to their home directory when they log onto a Windows
machine), and the files have disappeared.  Teachers have confirmed that
they've looked over the kids shoulders while they're saving files, and
checked when they were done by accessing the drive via My Computer, and
the files are there, but the next day they're gone.  Sometimes they say
a kid will write a file to the server, and not get any error message,
but when they go to My Computer, the file's no where to be found.  

Needless to say, my credibility is taking quite a beating.  Has anyone
else experienced this, and have any ideas how to put a stop to it?

On a slightly different subject, does anyone know how to get a linux
file system to do what we used to be able to do with Netware, ie just
launch some utility and see every file you've ever deleted that the file
system hasn't yet overwritten, and recover them at will?