I am experiencing this problem with MEP 17 and 18MX where I copy the the 1080 / 50P AVCHD/H264  MTS files from the SD card of my Panasonic SD900, to my AV harddrive and then drag them from the media pool to the timeline. Out of about 150 clips I get a group of about 10 which decide to create separate .WAV files of the soundtrack for each clip along with the HDP files, in the imported folder or sometimes the C:/.....Audio Temp folder.

The result of this is that the video associated with these WAVs plays very badly (stutters, does not play smoothly) in the timeline and if they are deleted along with the other HDP and reference files they just regenerate after reopening MEP. I have even tried deleting the problem clips and recopying them from the SD card but still the same result. These problem clips are all shot on the same camera on the same day and settings as other clips in the timeline that do not have this problem.

My set up is a Core2 Quad 2.83Ghz (oc to 3.4Ghz) 4GB ram, GTX460 1GB, Vista 32bit with all current hard and software updates and generally performs well. 

Anybody any ideas what might be causing this? A clue may be that the WAV, HDP and HO files of the problem clips are now only appearing in the C:/...Magix/ MEP MX /AudioTemp folder, instead of with the .MTS files on the E: AV Drive (where the HDP and HO files for the non problem clips generate.