[0.4.8] Saving an opened .pyxel file prompts "save a new file" dialog

Hello! Hot on the heels of the 0.4.7 save issue, I've discovered a similar (related?) problem in the 0.4.8 release. Whenever I open one of my .pyxel files, and then attempt to save it, it opens a "Save document as..." prompt, even though I'm just saving a pre-existing .pyxel file. Note that all subsequent attempts to save the doc work normally - it's just the first one after I've opened a .pyxel file.

Thanks much!