I need to v-vocal a couple of notes on a track, but when I open the v-vocal editor, I see the waveform in blue, but I don't have the yellow line that let's me edit the note.  I know that I can bounce to a new clip with a hotter level, but that's a hassle I really don't want for various reasons.  Is there a way to adjust the threshold on v-vocal so it will detect and edit my note without having to make it artificially loud?
 
Thanks,
Seth

I have the same issue with V-Vocal. Even on clips with plenty of gain, it does not map all notes.  I have to boost the gain way up, bounce the clip, then V-Vocal maps all the notes.  Clearly this is messy, and alters the mix of the clip relative to clips around it.
 
Bitflipper mentioned V-Vocal has a "gate" and will not recognize notes below a given threshold.  Does anybody know the threshold?  And can this threshold be adjusted?  That would make V-Vocal a lot more useful.
 

I just too a quick look at a vocal clip in v-vocal. It seems that the threshold is somewhere in the neighborhood of -24db. 
 
I would suggest that you try to get into the -18 db or above with your clip to eliminate detection issues.
 
If you are having trouble with matching levels perhaps raising the level on the entire clip you are going to edit first. Then apply v-vocal to the needed areas. Bounce them to clip after editing.
 
If this results in the track being too hot for the rest of the mix either use the gain reduction tool, or lower the trim on the track before mixing.

There is no user-accessible adjustment, AFAIK. Furthermore, the threshold depends on the material. For example, you can run a sine wave into V-Vocal and it will have no problem distinguishing the fundamental frequency even at -30db. An actual vocal clip might need to be -12db for V-V to reliably analyze it. If there is no strong fundamental at all, perhaps because the performance is very breathy, contains a lot of shouts and grunts, is pre-effected with chorus/delay/reverb, or a stereo track with large L-R differences, V-V may skip over large portions of the clip even though the amplitude is otherwise plenty high enough.
 
But try raising the level first. Rather than bouncing, use the more convenient Process -> Audio -> Gain to bring it up. Beware that if the problem isn't just level, but rather that the vocal clip is dirty, you may want to just re-track the part or punch in those couple of notes instead because even though V-V gave you a pitch line it may be mistaken or confused to the point where artifacts will be introduced.

bitflipper, Old question, but do you find V-Vocal and Melodyne equal in transparency, or do you think one introduces more artifacts and timbre shifts?  I think they handle formants differently.

Looks like in X2 (which I've recently switched to) the path has changed to Process -> Apply Effect -> Gain.  This is what I've always done in the past and then I'll use a clip volume envelope to bring it back down however many db I have to bring it up.  I guess that's what I'm going to be doing. 
 
On a single track it's not so bad, but in this case, I have to match up 2 violin takes and a sax take playing some exposed unison lines.  Each take was recorded with multiple mics that are blended to get the right tone and there are random notes here and there throughout the song where the players just weren't quite close enough.  With this v-vocal is detecting on some tracks of the take, but not on others - a close mic vs a room mic for example.  A threshold adjustment would make the process a lot faster.  Oh well....

Konrad: there is no question that Melodyne does a vastly superior job compared to V-Vocal. Its detection is better, it handles formants better, and it automatically adjusts slides in a transparent manner that takes practice to accomplish with V-Vocal. Even large pitch changes can be transparent with Melodyne. Plus it's just more full-featured all around.
 
However, I find that most of my pitch editing involves small changes to short chunks, light-duty alterations that V-Vocal can handle just fine. It's conveniently integrated into SONAR, making it very easy and fast to use for small touch-ups. It's also un-doable. That's why I still use V-Vocal, and actually use it much more often than Melodyne.