Which might be the problem ???

[Xpression]

Hi list, I've a FreeBSD-4.5 server running tacacs+, exim and
popa3d, it's working fine, no problem, but sometimes when I
reboot via: name_server# reboot I see this message...

Waiting for ..........
Waiting for ..........
Waiting for ..........
Syncing disks 1 2 1 2 1 2 1 3 4 1 1 1 1

(I always see this message but when it give me error is when
Syncing disks get too large the string)

...then saids me that message on init.

/kernel Mounting root from ufs: /dev/ad0s1a
/kernel WARNING: / was not properly dismounted

Any clues ???