Active Desktop settings keep changing

[gengakusha]

Can anyone give me any pointers on a frustrating problem. Something seems to be changing my Active Desktop settings.

I had a JPG set as my desktop. A day or two ago it disappeared and I was left with a single colour desktop.

Checking the settings I noticed that only BMPs were being displayed as potential images and the "web" tab had disappeared from the custom settings so I checked the registry. I found that the "NoActiveDesktop" key had been set to "1". I have tried setting it to "0" and deleting it altogether. In both cases the "web" tab reappears and the list of images in desktop properties shows JPGs again. However, if I select one it gets previewed in the settings dialog but I cannot apply it. If I click "OK" nothing happens (other than the dialog closing). If I click "Apply" it appears that I have clicked the button because it then greys out until I select another image, but again the image does not become my desktop.

Whichever change I make, after rebooting the machine the "NoActiveDesktop" value gets reset to "1". Very frustrating!

There is no "NoActiveDesktopChanges" key at all. I have also tried to add that but it has no effect on the problem.

It may or may not be relevant but I am changing the value of the key in HKLM. It doesn't appear in "Current User" at all.

Thanks