Shalom,
Many possible causes.
Check for stale NFS links, locked files with DP.
DP is not a good OS backup tool, because it can not produce bootable images. See Ignite for that.
SEP
Steven E Protter
Owner of ISN Corporation
http://isnamerica.com
http://hpuxconsulting.com
Sponsor: http://hpux.ws
Twitter: http://twitter.com/hpuxlinux
Founder http://newdatacloud.com