So far X2 is working quiet well.
After editing an audio clip with the external WaveEditor (Wavosaur) & saving, then back to Sonar asking me to reload it, I click Yes, and poof!! the clip is empty.
Checking the "Tool Copy ....." saved file by Wavosaur in the Temp Dir, It looks OK.
Anyone with different results ?
Thanks
UPDATE 
Sorry about that, it was my mistake.
It works fine :
I was working on a shortened clip and while editing the audio, I removed the silent parts changing the clip's length so when returning to Sonar the clip was of course misplaced.