Can not change root password?

[james watson]

When I typed in
mysqladmin -uroot password NEW-PASS where NEW-PASS is my password of choice

no errors

in order to verify the password for root
I typed in
mysql -uroot -p
I was prompted for a password. If ignored password and press enter, no problem
if enter the NEW-PASS
It gave me errors like this:
ERROR 1045: access denied for user: 'root@127.0.0.1' (using password:YES)

It seems that I am not able to change password for root.
Anybody know how to alter root password?

thanks