Slideshow goes to wrong aspect ratio

[DavidVale]

I use WMC mainly to play music. If I use the "show pictures" facility for a random slideshow there is often a problem with aspect ratio. It starts by showing the folders with black and white images OK, but after displaying the first photo within a folder for the first time, it suddenly clicks into a tall aspect ratio, 4:3 probably, and stays in that until I stop the slideshow.

It does not do this if I go into the pictures facility and play a slideshow of a selected folder. It only happens with the random slideshow to accompany music. Any suggestions?

Display is a Panasonic Viera LCD TV.

Thanks for any help,
David