It's not obvious to me. There's a 'rate' slider, but no 'sync to tempo' knob? Help.
LPMusic

Yes - that's the raison d'etre of the Rate drop down selector. Not sure which slider you are referring to.

Actually, from what I get of the reading of the manual, it's going to depend on the pattern, but in general, they should sync.  The manual says 'rhythmically' and 'hamonically', and when I use it, it seems to generally sync when I'm listening with the metronome on.
 
However, the manual does state that some files are created in 'free mode'.  If that's the case, then they get quantized to the nearest 1/128 note, which (I guess) should mean they are still on time, but at such a small resolution, may be tough to discern if they are drifting off time.
 
Speaking of drifting, I'm one of those who have seen midi note timings all over the place in previous versions of Sonar.  Since I have just recently started X2, I haven't tried it now, but CW has stated they have re-written a bunch of the Midi processing, so I'll have to see if it's better.  Some other posts I've seen says it has not gotten better.

i figured it out.....choose "notes" from the drop down menu. Viola.

you can double-check it by bouncing the clip with the arpeggiator on and see where the notes wind up.  you can move them around at will or quantize again.... just turn off the arpeggiator when you play the track back.