Upgrading from 2.3 to 2.4 workstation..public key doesn't work anymore.

[Roy]

My public key/password  authentication scheme doesn't work after upgrading 
from 2.3 to 2.4 workstation. I can un install 2.4 and the reinstall 2.3 
using all the same user files and it work fine again. This isn't true of 
all 2.4 workstations going to the same server. Some work.

I'm assuming this has been run into before, but couldn't find any thing 
searching my archives of this list.

Peace

Roy