How to: Apply master text format to a slide.
Solution:
In 'Slide' view, reapply the slide layout.
1) Select the 'View' menu and select 'Slides'.
2) Move to the slide to which the master text format is to be applied.
3) Select the 'Format' menu and select 'Slide Layout...'. (The Slide Layout dialog box appears, with the current layout selected.)
4) Click 'Reapply'.