Download showing "negative cts, previous timestamps might be wrong"

[Nick Payne]

I just downloaded the most recent episode of New Tricks in HD (series 11 
episode 8), and when I had a look at the cmd window after the download 
finished, it was full of the three messages like those copied below, 
repeated over and over with a different frame number for each set of 
three messages, though the download eventually seemed to complete 
successfully. Although the episode is the same time length as previous 
episodes, the downloaded file is about 50% larger (about 1.5Gb vs 1Gb 
for older episodes). I opened the downloaded MP4 into WMP and checked 
that it was playable at several random points, including the titles at 
the end, and the download seems to play ok. I'm running the most recent 
version of get_iplayer on Windows. Any suggestions on what has happened 
here?

[flv @ 02602c60] negative cts, previous timestamps might be wrong
     Last message repeated 612 times
frame=12336 fps=1644 q=-1.0 size=  214945kB time=00:08:13.44 
bitrate=3568.5kbits

Nick Payne