mounting msdos partitions buggy?

Is this happening to anyone else?

=======
localhost# mount -t msdos /dev/ad0s5 /mnt
localhost# touch testing
localhost# cp testing /mnt
localhost# ls -l /mnt/test*
-rwxr-xr-x  1 root  wheel  0 Jan 28 07:34 /mnt/testingg
localhost# mv /mnt/testingg /mnt/testing
mv: rename /mnt/testingg to /mnt/testing: File exists
localhost# rm /mnt/testing
rm: /mnt/testing: No such file or directory
localhost# rm /mnt/testingg
localhost# cd /mnt
localhost# touch testing
localhost# ls -l test*
-rwxr-xr-x  1 root  wheel  0 Jan 28 07:35 testingg
=======

localhost# uname -a
FreeBSD localhost.bsd-unix.org 5.2-CURRENT FreeBSD 5.2-CURRENT #0: Mon
Jan 26 17:14:28 MST 2004    
cas_at_localhost.bsd-unix.org:/usr/obj/usr/src/sys/CASX64  amd64