Ubuntu Linux ver 9.10. Have been trying to fly with Ubuntu for a couple of weeks, installed without problems, bought the book, downloaded the command cheat sheets, experimented offline - no major hassles.
I now have a problem with the user password when trying to use the sudo command (and it has been working). I've done something which stops the user password being entered, the password bullets do not appear on-screen and a blank password is not accepted. I appreciate that a re-install will probably fix this but don't want to get into the habit of re-installing to fix what could be simple to rectify. Re-booting does not fix the problem. Any ideas appreciated.