I think that it should be in the 'Software Center' submenu. I found it in 'File Tools'. I also cannot make out what the icons are supposed to represent with a 28 pixel panel. Otherwise, everything seems to work as expected.
The icon reads "uN" for update notifier.
The important think about the icon is its color since thats the primary way it communicates with the user.
It works as following.
After it is started,it waits for 5 minutes before checking if its time to check for updates or not.
By defaul,it will try to check for updates only after atleast 24 hours have passed since the last check.
The default state where there are no updated has the icon in greenish color.
If there are no updates,the icon will be in "passive state" and hence an "auto" system tray option for it will have it hidden.
If if finds updates,the icon changes to reddish color and will be in "need attention state" and an "auto" system tray option will have the icon displayed ie,not hidden.
The icon changes its color to a whitish when its checking for updates
The tool tip will also tell you if there are no updates or if there are updates.
Right click on the icon and should see various options.You can check for logs to see what is happening.