Read this thread : Bootcamp Partition Error: "Files cannot be moved".
The thread is quite long (so you might start from the end). I quote the last entry:
This happened to me before, and I
managed to fix it.
I booted from my
Snow Leopard disk and ran disk utility
and verified and repaired the disk AND
the disk permissions.
Other advice is:
- Reinstall OS - Boot Camp's recommended solution. Very time
consuming.
- Defragment - Requires purchasing iDefrag for $30. Defragment your
internal (boot. drive and try Boot
Camp again.
- Clone & restore - Requires free SuperDuper. Backup your internal drive
to another drive, erase the internal
drive, then restore the backup to the
internal drive. This is essentially
another way to defragment.
- Manual partition resize - Boot from an OSX DVD, run Disk Utility from
there, shrink the OSX partition on
your internal drive, then create a new
FAT partition in the free space, then
format the FAT partition to NTFS when
installing Windows.
- Apple Tech support's solution - Startup machine with Command + S. Run
/sbin/fsck -fy. Repeat process. Reboot
and run Boot Camp.
- Clean startup - Reboot your machine. Run Boot Camp before running
anything else.
- Move large files - Moving large files (videos, Parallels VMs, etc.. to
an external drive allows Boot Camp to
proceed for some.
- Disk Utility - Run Disk Utility and perform zero free space, repair
permissions, and repair disk. Some of
these may not be necessary (zero free
space probably makes no difference. -
but it doesn't hurt to do all three.
NOTE: You should probably boot from an
OSX install DVD so Disk Utility has
full access to the internal boot
drive. If you don't have the DVD, you
can boot from a cloned drive you
previously made by holding down Option
at machine startup. See 3. above for
how to clone your drive.
EDIT
Since you ask about how does Mac automated defrag work, here is a description:
To clarify, there are 2 separate file optimizations going on here.
The first is automatic file defragmentation. When a file is opened, if it is highly fragmented (8+ fragments) and under 20MB in size, it is defragmented. This works by just moving the file to a new, arbitrary, location. This only happens on Journaled HFS+ volumes.
The second is the "Adaptive Hot File Clustering". Over a period of days, the OS keeps track of files that are read frequently - these are files under 10MB, and which are never written to. At the end of each tracking cycle, the "hottest" files (the files that have been read the most times) are moved to a "hotband" on the disk - this is a part of the disk which is particularly fast given the physical disk characteristics (currently sized at 5MB per GB). "Cold" files are evicted to make room. As a side effect of being moved into the hotband, files are defragmented. Currently, AHFC only works on the boot volume, and only for Journaled HFS+ volumes over 10GB.
So unless Journalling is on by default in Panther Client install, neither of these optimisations will run.
It seems that if Journalling is on, OS X does scatter the files around the disk in the name of optimization. This might explain some of your problems. It might be that defragmentation will negate this effect, or it might be that reinstalling without Journalling is the solution.