I should start out by stating that I did not find this solution, but merely tried what somebody else suggested on SourceForge. So here we go:
There is a bug in a configuration file of Simple Backup Config, were a function call is missing a parameter, causing the process you start with the "Backup Now" Button to immediately go Zombie.
Here is the how to fix, step by step:
Find the following function: def on_backupnow_clicked(self, *args):
sudo gedit /usr/share/sbackup/simple-backup-config.py
Once you find it, edit the next line, which looks like this:
pid = os.spawnl( os.P_NOWAIT, self.conf.get("places", "prefix") + "/sbin/sbackupd" )
edit to look like the code box below:
Don't forget to save..
pid = os.spawnl( os.P_NOWAIT, self.conf.get("places", "prefix") + "/sbin/sbackupd", "/dev/null" )
You are now back in business, the "Backup Now" button will work again.