Regarding the memory, is it best to reboot once in a while - I must admit I had been playing it for a good few hours (finally had the time to give the add on a good go) when the error occurred.

Only the sound of the videos - when a competitor or uncle talks.
This is a clean restart with all the patches installed from start. The speech was fine until opened a another new counting office (I think this was Hamburg) then the sound went. This also coincided with the the known bug -:

'The game has suddenly developed a problem with the event news - the the video for a new ship froze, then the next news item was blank. I restarted but now all historical event items are messed up such as 'T-' showing.
I am four years into the game and have not had problem until now and now I can't fix it.'