Switching an installation from SU to CU or vice versa, spawning a repair, or modifying from the installation DVD after installing 9.2 Service Pack 1, produces an error that prompts an uninstall.
I checked and starting a repair or modify process from Add/Remove programs still works and does not produce this error, however many times this is not a viable method as the network installation point or media is no longer available...and users will need to manually modify the registry to switch between CU and SU, following KB24741.