All,
Thankfully I have a lab machine and don't have to do this on a PRODUCTION unit. I went so far as removing my working installation of BE 9.1 SP3 with HF54, cleaning the registry, rebooting the machine, reloading BE 9.1 SP2 with HF50,51, & 52, then applied the upgrade to SP4 and it works. It certainly appears that the "checkfordependencies.MSI" process that is being used has a glitch, when you root around and find the temp folder that holds the upgrade files and read the patch.ini file it always ends up saying it needs the BE91SP2.exe. I agree with Ken that the SP4 process is broken and needs to be fixed, since removing the whole program and then reloading it on production systems is not acceptable.
The Veritas support folks should resolve this immediately, I guess I am going to work thru my local Symantec representative, to let them know of my displeasure with this whole process, and would suggest that everyone do the same.