SpyBot S+D beta - removes screen destop background

Hi

I am using Spybot 2.0.5.0 build 20110804 on a laptop with Vista SP2.

Everytime I run the full immunisation process, my desktop background photo does not display. The photo is a simple jpeg file in Documents/My Pictures and was set up using the Vista desktop customisation dialogue.

When I backout the S+D immunisation, my desktop background image re-appears as normal.

Any idea why this is occurring?

Thanks