UPDATE: I found the problem! I wasn't missing a prop texture, it was an engine texture that was missing from the passenger textures with the bare metal props. I simply copied the engine textures from another folder that I know was working correctly. All is good!
I have FSX, MAAM-SIM edition 10, and I used the self installer from the downloaded version. It seems to only affect the silver bladed props, all the black props are ok. I'm running Windows XP.
Note: I am aware of the texture "fix" that is included in the add on of different prop tips. Still have the same problem.
I noticed that on all my passenger DC-3 props, the spinner dome, and the blades are not connected to anything. The prop hub is invisible. Anybody else have this?