hello
yesterday i record a audio "guitar" in sonar x1 and il like to create grove clip looping, but every time i try to do it the wave will strech or shrink.
i am my doing something wrong?
please help!
JP
 

Same thing happens in X2a

you need to go to the inspector and manually type in the data.
sonar makes a best guess at your loops, sometimes it gets close, other times the audio data is so condensed and hard to interpret it cant make a proper estimate.

in the track inspector you will see by changing values from say 12 to 8, your BPM, or tempo will change,
keep changing this until you see a ball park figure of your tempo you played it in.
experiment.
 

I have this a lot. 
I haven't tried Chucks idea and will, but I also find if I have slip edited the clip, I hit Apply Trimming before Groove clip looping and it often works.

Groove Clipping guitar can be quite challenging at times...it will test you in a lot of ways and especially your playing and timing...I personally rarely loop guitar parts , as I lose the feel while playing...I also don't want what I write to sound so mechanical...but at times it is needed. As stated above, I never let Sonar guesss for me...I take Charlie and MGM's approach..and trimming also helps GREATLY,as ANY slight artifact hanging off the beginning or end can wreak havoc...