Hi; I have a problem with showing my photos and images to some one. Every time I click an image or photo Gimp starts

. How do I change this so that GPicView starts instead of Gimp. I like Gimp and use it at times but for showing an image or photo I would prefer GPicView. I know I can right click on the image and select GPicView for the menu but I would like to just click the image and have it start automatically and show the image or photo. In the past if I selected GPicView from the menu it would become the default for that image or photo. That doesn't seem to work anymore. I'm using the latest version of PCLinuxOs with the LXDE all current in updating. Any body have any suggestions?
Thank you, Steve