Assisted a customer with upgrade on Solaris 10 recently.
Experienced the failure documented in this TechNote: seer.entsupport.symantec.com/docs/325408.htm
Just keep the original 6.5 install media handy. The solution is to remove VRTSpbx and VRTSicsco and reinstall before re-attempting the patch install.
All went fine after that.
Just perform the normal precaution steps - ensure you have a catalog backup.

I faced with this problem http://www.symantec.com/connect/blogs/netbackup-654-upgrade-using-sun-patches-important
It's to hard to know all possible problems but you have to crete a "plan B" if everything will go by wrong way. Most upgrades goes normally.

But I did document an upgrade from 6.5.1 to 6.5.4 on a Solaris 9 Master.

I will definately be sure to remove pbx before the upgrade.  I looked around before making the thread and nothing popped up, so I probalby would not have found that issue until it was staring me in the face during the actual upgrade.

h-hour

I really hope this goes smoothly.

*knocks on wood

The binaries were installed without issue.  I'm performing my test backups now.

  Rjrumfelt,
Be sure to review the 6.5.4 late breaking news, TN 324985, known issues are documented there.  Review the known issues, if you're suffering from one or there other, be sure to acquire the EEBs related to the fixes.