Found by druden & confirmed by ronilse

If yo open Teletext "home" (MP Home -> My TV -> Teletext) & try to use the "button fullscreen" yo're taken to Fullscreen TV & not Teletext in fullscreen.

h4. Steps to Reproduce
Start MP -> MyTV & open a channel with Teletext -> Select button Teletext & wait for Teletext page to load -> Select button Fullscreen (left menu in B2), Teletext page it’s hidden & Fullscreen TV shows instead.

h4. Additional Information
If you have a MCE remote with Teletext button, that one works from fullscreen TV.

NB! It’s the same results with "Use separate thread to render GUI" enabled/disabled.

Bug thread on forum located here:
http://forum.team-mediaportal.com/showthread.php?t=13216