magixzap,

Sorry I don't have Photostory, but the interface shown on the Magix site shows it to very similar to the editing programs I use eg Movie Edit Pro.

To ungroup audio and video you need to be in 'Timeline mode' where all object are shown on tracks which indicate playing time. A standard video clip occupies two adjacent tracks -- one for picture and one  for sound underneath. If you want to remove the audio use the 'Ungroup' icon which looks like a chain with broken links. An alternate is to simply mute the audio object. You may find the tutorial helpful at: http://www.magix.com/us/photostory-on-cd-dvd/detail/tutorials/

Regards,

Carl