Like documented from Drupal, '#title', and '#description' given in the implementation of hook_menu() don't need to contain strings passed through t() because the core module responsible for the creation of the Drupal menu system will pass them to t() before to use them.
With the implementation of hook_menu() given by the project module, the function will be called twice: one from the module, and one from the core code.
Comments
Comment #1
avpadernoThis is clearly stated in Menu item title and description callbacks, localization, where there is written Titles and Descriptions should no longer be wrapped in t().
Comment #2
Zohar.Babin commentedfixed in 6.x-1.4