There is no hidden meaning in that statement. I am in no way hinting that you are crazy. Cheesy
I wouldn't have thought so

I think you might have hit the spot with the xfce settings... it seems the most plausible explanation, given that the problem shows up with both 5.8 and 5.9 .
Now what that setting might be, I don't know.
Since I'm still "testing" with 5.9, I'll soon reinstall it, and try the icon with a fresh intall to see if the problem is still there.
Right now, my problem is not so much the icon (that I got to run by setting Terminal=true), but that whenever I try to actually print the file (or use the right-click context option), I get a segmentation fault and nothing comes out (opened another thread for that).
Thank you all for the ideas!