That could be a good way to solve it, but would you still do this considering that I'm going to be using this DVD as part of job applications within the UK? It's very important that there wont be problems with the playback Image may be NSFW.
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I just tried to create another sequence with 25 fps, and then I copied everything over from the old sequence - and I went to 'interpret footage' and set my clips to 25 fps. This renders smoothly (only tested on my PC though), but it's a bit of a mess to make since it messes up my timeline by inserting quite a few empty spaces - so I have to do a lot of small adjusments.
I'm in doubt if I can just skip doing the new sequence and just do the second step with interpret footage and still use the old sequence - this causes less of a mess in my timeline, but I suspect it is of some importance that the sequence framerate is the same as the export framerate?