Hi,
I have two Humax 1100s and the subtitles on recordings will frequently jump significantly ahead of the audio on both boxes.
This can be brought back into sync by stopping and resuming playback. There is no problem with subtitles on live TV. The problem is new(ish) and appears to have got much worse lately (happening every few minutes).
Since the problem is apparent on 2 independent 1100s I have to assume it is a firmware problem, or possibly a broadcaster problem (?) as suggested via a google search and where I found an older similar posting.
Both boxes have the latest firmware update (UKFSA 3.00.96)