Problem with transcoding some HD programmes

[Shevek]

I am having some problems with the transcoding to MP4 of some programmes.

E.g. The_Great_British_Story_-_A_Peoples_History_1._Britannia

I got this error from ffmpeg:

[mp4 @ 044F5700] Application provided invalid, non monotonically increasing dts
to muxer in stream 1: 86800368 >= 86642688

which stopped ffmpeg and left me with the flv file.

I updated to the latest build of ffmpeg from Zeranoe and used --force
to attempt to transcode the already downloaded flv and now I get
repeated warnings from ffmpeg:

[mp4 @ 01d4ba60] pts has no value
DTS 1839840, next:1843160000 st:0 invalid dropping
PTS 1840040, next:1843160000 invalid dropping st:0
DTS 1839872, next:1843199122 st:1 invalid dropping
PTS 1839872, next:1843199122 invalid dropping st:1

The transcoding did finish and then get_iplayer successfully tagged the MP4

Any pointers?

TIA