[Brian Gew]

[Chris Craig] ” when i change my AV receiver over from my TV to my MiniMac ( after having watched my TV for a while ), my desktop has reverted back to the constantly changing pictures again.”

Try This:

Open your finder window.
In the left hand bar under places choose your user name (house icon).
Once clicked scroll down and open the”folder named “Library”.
Scroll down and open the folder titled preferences.
Pick the file titled “com.apple.desktop.plist”.
Drag this file to the trash and it should stop.

Let me know if that works.