Hi Barry I am trying to keep it simple, cos simple usually works. I am using the latest version of PTE5, downloaded yesterday. I've converted the WAV to MP3 and its now 3mb in size, but the problem persists. There are currently on 24 images in the show (more to be added), but the timing problem is in the first 10. The slides are put together in the timeline so as to change at a specific point in the music. When the PLAY option is used from the timeline, the slides and music are exactly how I want them (slide 5 starts after 8 seconds of music, slide 9 after 16 seconds). If I select PREVIEW from the timeline, or from the main screen, the music plays as expected, the first slide starts on time but subsequent ones are out of sync. After 8 seconds slide 4 is still on screen and about to change, and after 16 seconds slide 8 is just starting. These are the same files but the Preview seems to load slower? The JPEG images were converted from RAW files and average 900K in size (but this size has never been a problem before).