Korg TR and Sonar

[Piano Devil]

I've tried to ask everyone about this. Can anyone here help me?

Here's the situation:
When I connect Korg TR to Sonar 8.5 through USB,
I can record and listen to it and everything seems to be fine.
BUT, the sound is lame.
Even if I listen to it through Korgs earphone plug.

When i disconnect Korg from Sonar and turn 'local control' ON,
I realise that the sound in Korg is now more thick and strong. Much larger.
And I can also hear the differences between sounds easier.

When using Sonar, the sounds loose their strength.
I really don't know where or how to locate the problem.
Anyone...?