ubuntu root password

Hi,
i've installed ubuntu 11.4 virtutal machine on parallels desktop for mac.
After install, a wizard asked me to set a password. I did it, and i can access ubuntu after login as "parallels" user.

The problem:
for certain commands like sudo in the terminal, i recieve a prompt asking for parallels password. The one i've defined during ubuntu install doesn't work.

It's very surprising since i can connect to ubuntu with it.
After reading google + this forum and tutorials, i've tried "parallels", "123", "1234", "0000" for the password. None of the are working.

I've also tried to reset password in recovery mode. It works for the ubuntu login access...but when i type a sudo command and type the same passord, it is refused!

I've also tried to install a java package through apt command. Same thing : prompt for password in graphical interface, but the password i've defined is not correct for root.

The user name seems to be "parallels". What am i supposed to do for the password?
Thanks a lot for your help.

 

http://forum.parallels.com/showthread.php?t=114176

 

I'm on my last wire right now, I've been trying to get Steam onto Ubuntu for hours on end, with small baby steps all the way through. I have tried countless passwords to be allowed to download Steam, and I cannot get it to work. I have found myself screaming at my Mac over and over because I have tried everything that the internet has given me. I don't know what to do.