MultiSkype allows to receive notifications from multiple Skype profiles at once.
The user of MultiSkype should understand some details to be able to use it successfully.
1. It is executable file (.exe). Not an add-on, plug-in, script, etc. Just executable.
2.While starting it attaches to all Skypes you are currently running. Any Skype started after start of MultiSkype is not managed by MultiSkype. So, if you restart one of Skypes, you should restart MultiSkype too or 'Update Skypes list' from tray icon context menu.
Before reporting a bug please check that all Skypes are attached. Right clilck on MultiSkype tray icon, choose Settings. Under "List of monitored Skypes:" you will see all attached Skypes. If some of Skypes aren't there please try to 'Update Skypes'.