Q: How do I remove unwanted page tabs in drupal 6?
A: Follow the instructions in this article - http://drupal.org/node/483324

Yet another post about trimming away unwanted stuff from drupal so that your website better matches your target web design! This time it's about removing unwanted page tabs. In my case I wanted to remove to tabs from the userplus module's screen - the 'assign user roles' and 'assign user groups' tabs. The client doesn't want them so they just have to go!

This approach assumes you have written (or are going to write) a module but after that it is quite easy.

Following the instructions on the above mentioned page I just added the following function to my module (called communication_centre), cleared the cache and the tabs happily disappeared!!