xdg-open and libreoffice

hi all! Looks like a little GNOME just hit me with a club: I'm working on a presentation with libreoffice impress (yes, I hnow, why ...). Now that thing has a function "Edit image using external tool". Selecting that, impress calls "xdg-open file://tmp/sdfsfewf.png" - which call in my case kuickshow - which is not surprising, as I use kuickshow for viewing images. But how do I persuade that piece of a genius to call gimp ??? Nik -- Please do not email me anything that you are not comfortable also sharing with the NSA, CIA ...