I have 3 servers all running solaris 9 using ssh
I changed the root passwd on all 3 a few months ago.

I cannot log in as root currently as it wont accept password.
I try to su from another user to root - when I type the password that I know to be correct it rejects the password immediately (no delay) with error su: sorry

If I type an incorrect password it takes several seconds to return to the prompt..
I think the password I am using is correct but something else may be wrong.. No changes made - only other thing it could be to do with is password again or expiry...

Any suggestions - I am in desperate need of help as I cannot log in as root on any of these servers as a result...

Is it possible the root password's expired? If the root account password has expired, you won't be able to log in as root from another user (su). You'll get an immediate response from the correct password and a delay from an invalid one. Your only option is to log in as root from the console.

You might consider installing a script that notifies you when account passwords are due to expire and you should install sudo. Then your account can have root priv's and you can reset root's password.

Carl