shadow problem

[Richard B. Pyne]

I updated shadow to version 4.1.4.3 and it left me without su and unable 
to log in from the console. I had to log in as single and resurrect 
version 4.1.4.2 to be able log in.

Any suggestions? I like to keep things fairly current, but this was a 
nightmare to figure out what was going on. The best clue was that even 
though I couldn't log in from the console I could ssh in but then 
couldn't su to any other user because /bin/su was missing.

--Richard