There seems to be something wrong with the script, at least in my case.
When trying to start Start-Up Manager from the menus, it just blinks on the screen and then closes. Starting it from the terminal gives this:
$ sudo /usr/bin/startup-manager.py
(startup-manager.py:10556): libgnomevfs-WARNING **: Failed to open session DBUS connection: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken.
Volume monitoring will not work.
Traceback (most recent call last):
File "/usr/bin/startup-manager.py", line 649, in ?
sumGui = SumGui()
File "/usr/bin/startup-manager.py", line 642, in __init__
File "/usr/bin/startup-manager.py", line 568, in update_widgets
TypeError: a float is required