I've had issues with 9d and been emailing a very helpful lady at Sony USA.
Now, call me stupid but it seems that the 'UPDATE' is, in fact a 'WHOLE PROGRAM'!
So, having UNINSTALLED 9C, just run the 'UPDATE' and enter your serial number and off we go!
I'm quite prepared to be shot down on this but it seems OK to me.
Now if only Sony were to tell us to do this instead......
Hope this can help y'all!
Oliver.

All of Sony's "updates" are full version installs. It will install over the top but it never hurts to uninstall and reinstall when going to the next "letter" update.

Well, I learnt something new today!
It seems to have solved all my issues.
Just wish the info was clearly visible when downloading :(
Ah well, all's well that ends well.
Oliver.