So, we performed a shutdown immediate of a 10.1.0.3 instance, then took a cold backup, and upgraded to 10.1.0.5. This version had a severe bug which crippled one of our apps, so we decided to revert back to 10.1.0.3. No prob, we had everything stored in /u01 (ORACLE_HOME) and /u02 (datafiles).
We restored these, and the database opened, albeit with corrupted datablocks which we didn't catch until our RMAN backups started. Our RMAN backups and archivelogs are sent /u03, which we didn't restore. The way we looked at it, the archivelogs created after the 10.1.0.5 upgrade wouldn't be recognized by the restored controlfile, and the one's needed for an instance recovery were still there from before the upgrade.
When we tried to run
RMAN> BACKUP VALIDATE DATABASE;
RMAN> BLOCKRECOVER CORRUPTION LIST;
We're started getting an error message that the SYSTEM01.dbf file is newer than the version in the controlfile. We're sort of confounded now. Is there something in this scenario that sounds like we've done wrong?