I update my Rockbox every few days and for some time I have a problem with Pictureflow on Sansa Fuze v1. It occurs with "undefined instruction" error while trying to return to WPS from Pictureflow menu or when WPS integration is enabled and plugin should return to WPS after chosing album. I also noticed, that it works correctly when I choose Pictureflow from main menu -> plugins. It crashes when launched from context menu or by hotkey.
Rockbox version I have on my Fuze: r27960