I'm using PTE 4.3... On the timeline, if I reduce the space between transition effects too much, the sequence 'jams' and the same image and effect is repeated. I assume this is due to lack of speed from my 350MHz processor. The minimum spacing appears to be affected by the type of effect, whether the sound is a wav file or an mp3 (which presumably takes more processing resources), and whether the sequence is viewed as a preview or as the final exe file. Apart from upgrading my computer, has anyone any advice on this? The other factor that may affect it is the transition (?) width for the effect.