I don't know if this happens to anybody else, but it does to me and it compromises one of the most basic things a desktop is made of.
Right click on an image > Set as desktop background is not working for me. It seems that this option is related to the explorer.exe shell because when I use it on a picture the background doesnt change while running bblean, but if I swtich to explorer.exe as main shell and log out/in I get the picture I had previously set as background. And once I'm back on bblean I get the one I had on bblean, so they are pretty much exclusive to each shell.
Drag and drop is a great idea, the problem is that it stretches the image to your resolution and most of the time this is a problem because the ratio is never the same and the image gets all messed up. In fact, images that are meant to be used as a pattern to form a background don't work at all because of this. As far as I know there is no way to make the picture retain It's original size unless you set the background via text on the style.rc file. The problem with this method is that it ends up being way too time consuming for some of us who have big libraries of backgrounds organized among many folders and like to change them constantly because you have to look up the file name and location every time (and in my case I have file names hidden for pictures by default so that's another step I have to go through) and go to the style.rc file and change it just to see how it looks.
In conclusion, it would be great if you could enable a method that allows you to set a file as background without it being resized. Maybe some setting could be added under the blackbox > configuration > graphics menu so you can choose what drag and drop does (stretch/center/pattern).