Running times !

[ToiletDuck]

Btw, i don't just convert Retail subs to match speed, but also Resolution 720*576 → 1080p

Those are different steps. One changes the info in the timings in the idx file while the other changes the images.

You don't say.. Hence i wrote 480p → 1080p 

But, what on earth could cause that on retail discs ?

Different cuts&co are normal for DVD and Blu-ray releases, especially if they target different regions of the world.

That's just it !?  both DVD & bd release are normal editions.. Nothing special.. i.e: DC, Uncut.. E.E etc.. etc.. 
Fyi, i never have seen special editions for episode discs, only movies!  ↔ Apart from the extra features that are onboard ..

Why? Isn't that obvious?  if the a/v output is 24fps .. and the source 25fps..  Not only a/v needs to be converted to match the framerate → speed/scaling factor.. right

If just the playback speed differs, for the video only the playback speed needs to be adjusted.
Sure, there are tons of ways to do norm conversions (PAL <> NTSC etc.), but then the frame count and content differs.
Cu Selur

 
You lost me there !?  
When you talk about playback speed i think about playback → Speed Rate (1x, 2x...) , and to me thats not the same as duration/play length wich is defined by the framerate in this case  

Right !? 

Also, when you change playlength of video wich is often the result of the framerate change, audio and all other tracks need to follow to match same duration , isnt it?

I don't get what you mean , My Royal Majesty Sir Selur