One more question: have you ever saved SONAR Preferences? Clean SONAR install has not created all registry keys Duckbar may require.  Easy check: open SONAR Preferences and click Apply.
 

no go for me either...

Terrasin, Loptec and smallstonefan,
check this: http://www.sonarmods.com/...x.php/topic,929.0.html

Here's my error logs: http://tny.cz/d5e13f29
There was no log.txt or firstrun.txt

Do you see duckbar-init  file in %appdata%\SONAR Mods\Duckbar ?

I do have the duckbar-init file there.

TerraSin,
try this update: http://www.sonarmods.com/sonarmods/forum/index.php?action=downloads;sa=view;down=271
 
...and see if anything is captured in the log file now.

Got it to open finally but when I went to choose which Sonar to use (because I have both X2 and X3 on my system), it crashed out again with the same error. When reopened, I have all the menu options at the top till I click on the bar, then they all disappear and all that is left is Help.

Could you copy & paste log file?
Empty menubar = Duckline is in offline mode. Right-click Duckbar icon to open settings:
 

 
What X3 build version do you have? Latest is X3e build 352.
 
 

Thanks Panu - it's now running for me on win 8.1 with your latest build!