Registry problem after changing the desktop background

After changing the desktop wallpaper over the desktop control panel applet, the corresponding registry
key is shown incorrectly in the registry editor.

Steps to reproduce:

• Open the desktop preferences
• On the desktop tab, select a wallpaper and apply it
• Open the registry editor and navigate to "HKEY_CURRENT_USER\Control Panel\Desktop"
• Fire up the value editor for the value "Wallpaper"

In the value editor, the value sometimes shows correct, sometimes has trash appended to it,
doesn't show at all or shows just trash. As the value is not always shown incorrectly,
one should close and reopen the value editor if the first try doesn't give the excepted results.

The problem seems to not happen if the value is changed by other ways, for example over the
registry editor. Also I haven't noticed the issue in the value list itself so far.