Digital Light & Color

It may be a feature, but I'll report it anyway:

In RAW dialog, hitting Apply button can produce several versions of the same RAW file. But clicking on a RAW file in browser, if such file has been processed previously and the output is opened in an image window, fails silently. If a copy of the processed image window is made and the original image closed, one can open the RAW image again.

Right. If an image of any kind, including raw, is already open, clicking on the image in the browser does not open another copy but instead displays the open window. This prevents accidentally opening additional copies of an image and then having conflicting edits. However as you say if you dliberately want to open more than one copy you can simply copy the open image. The intent is not to prevent opening multiple copies when they are really wanted -- only to make it harder to do so inadvertently.

Kiril