This is surely to be a simple fix. I'm not sure what might have caused it, but SONAR doesn't display the usual dialogue box when starting. I just installed X3 a few days ago and I was getting the dialogue box for a while and then it just stopped. I've looked through Preferences a few times and didn't see anything that would enable or disable this functionality, so I have no idea what I might have done. 
 
Any idea how to get it back? I kind of like having it.
 
Thanks!
John

From the main menu Help > Quick Start and check the "SHOW THIS AT STARTUP" option

Nice! I knew it would be easy. I have no idea how I stopped it from happening in the first place. 
 
Many thanks!
John