not sure, but try:
# In k3b's setup/preferences, there is a place to look for plugins, etc. You might need to point something to your file, or do an "auto scan" type thang
#2 Might growisofs need to be chmod 777 ...? Making it executable might be something, but as I am at a friend's place w/o Linux
I am not able to look at my own machine
good luck, lemme know!