Harmy, if you are using 1080p25 you will come across more compatibility problems when using AVCHD & Blu-Ray structures as it is not part of the Blu-Ray standard originally. Older blu-ray players DO NOT support 1080p25.

Convert the audio from 25fps to 23.976fps using EAC3to, then load up the M2TS file you created in MultiAVCHD (your AVCHD folder), change the framerate of your video from 25fps to 24000/1001 (this won't re-encode the video). If it loads up the original audio tracks remove those in the track selection and add your new 23.976fps versions. then you can output the AVCHD which seems to be a lot more compatible than MultiAVCHD even 3.0

The stuttering in EP4 is because it is adding 1 extra frame per second to change it to 25fps from 24fps. You should have run it though TSMuxer first to change the framerate and you would not have had any stuttering. Powerdirector is pretty crap at framerate conversions. It either adds or deletes frames to get it to the selected output framerate.

If you were having problems with framerate issues you should have asked for help in here first before continuing because you will find that no one will want to download your AVCHD because of these problems, plus the 1080p25 problems will also put people off