Comment 4 for bug 394946

I found out what was the bug. When you select a random path, I coded so that no preview was selected as it should be. The problem with the list control in wxpython is that when everything is deselected, it does not any more react. So this means that the last selection will stay visible. Not optimal, but far better as everything stays functional.

I've also improved the dialog. For example if you select a file from the library with the browse button, it will be recognized. The preview will be selected and its label will be used.