problems with command su

Vladimir E. Rodriguez
2004-12-07T16:01:31Z

Hello, I'm new user in linux community. I have installed in my computer
mandrake linux 10.0

Sometime ago it was working normal without problems. After that I changed the
root password, always that I want to change something in the configuration of
the system, I run su from other user (vladimir).

But the system says 'invalid password'. I tried the old, and new password, but
it doesn't work

I have to logout, and login with root to change some configurations.

Anyone could help me!!

thank you

Vladimir