Sorry folks for the new thread. I've checked a number of threads regarding Melodyne and did not find a proper answer.
After making a fresh install of Sonar X3 (replaced HDD) and installing all the updates (Xb to Xe) when starting Melodyne from inside Sonar I've got the message that my Melodyne is not registered.
I double-checked my Cakewalk Store (My Products) records I only found Cakewalk X3 itself and CA-2A Levelling Amp, no Melodyne.
All *.dlls are placed properly and show (right-click) a proper version (2.1.5).
What should I do?
Many thanks in advance. 
 

If you ever installed and registered Melodyne before; you created an account at Celemony. Your registered version should be available from your account on their site.