Could it be a teletxt hard of hearing service, try the black buttons at the top left of the remote (under the tv power button , think it may be the first one to the left of the av button)
Only guessing though
- - - Updated - - -
Tested it here, and gives me the same results your seeing on vix image.
Press button to the left of av button on vu remote, scroll down to DVB English, press ok (you may need to do this twice as subtitles seem to toggle between white, then white with black surround, then off)
Hope this helps.
