Okay, thanks, that helps guide it... I tried looking for ffmpeg commits, but realised that it could just as likely be dvdplayer or some other module. However, I'm getting fed up of recompiling vast tracts of code (be thankful for ccache...), so I'll take that leap of faith!
Anyway, I only just realised that I'm wasting time trying to find the error post-Dharma's release as I was (i.e. assuming it was working in early March since Dharma was released then). Dharma branched from Main in July of last year... I suspect the bug only appeared for me when Main was merged back into Dushmaniac's PVR build (possibly this commit
So, having floundered around with a couple of later code releases to try to move closer to the early March Dharma release date (which is pointless - d'oh!), I've gone waaaay back in time to prove that point...
17/03/11 Pre-11.0 GIT:6a77cd2 FAIL
14/03/11 Pre-11.0 GIT:0cee457 FAIL
01/03/11 Pre-11.0 GIT:b3283ad FAIL
... so, let's head for when Dharma branched:
16/07/10 Pre-10.5 r31900 PASS
Right. Another reference point - I'll use your February tip to see if I can get closer without splitting between July 2010 and March 2011.