While adding a ufs filesystem to the zone there is only special device can be given in the page.
if we need to add a device like /c0t0d0s0 to be mounted to /<filesystem> on the zone. raw device cannot be entered. This leads unverified mount point in the zone.
What exact device are you entering? If you enter something like /dev/dsk/c0t0d0s0 , Webmin will use /dev/rdsk/c0t0d0s0 as the raw device ..