I'm having problems with Melodyne exporting audio after time stretch (Sonar X3c producer, separately purchased full Melodyne editor).  I slowed some vocal passages to 200% original length by splitting a portion of the track to a clip and making the clip a region fx.  The first time I exported a wav file, the results were fine.  Now, a few days later, when I export the track (has several melodyne region fx clips) or even one clip, it sounds like sonar is exporting the clip at 400% original length.  When I tried to remove the region fx, the clip length stayed at its stretched length and the audio stutters.  I can edit the RFX stretch back to 100% and then remove the melodyne rfx and the audio sounds normal.  Does anyone know what's going on?  I'd like to be able to export a wav file agian after tweaking the region fx, etc.  But more importantly, I'm trying to learn how to avoid this situation later when I start using region fx melodyne with my music.
 
Also, are region FX clips (split from a single long clip) destructive edits?  I'm asking because Sonar seems to automatically make small wav files named e.g. Track 1 (Bounced, 427) when I split a clip and add a region FX. Excuse me if this is a newbie question, it's been a while since I've run Sonar.

Can you elaborate on the steps used to change the clip length to 200% using Melodyne?   I've only ever adjusted clip length by % using Ctrl+Stretch, and modified blobs within Melodyne, so I'm not completely connecting the two.
 
For your second question, yes, a Region FX is a separate bounced wave file, independent of the original.  But the Region FX itself is still "live" until that clip is manually bounced down.
 

Thanks very much. Yes, I stretched Using ctrl-stretch after creating the region fx - as recommended by melodyne manual. I want to add that playback thru Sonar sounds like I expect it to: 200% stretch and sounding excellent. It's only when I bounce to track or export audio that it screws up. Very strange behavior. Allow stretching under clip properties Audiosnap is enabled. Sonar wont let me stretch if disabled. Maybe Audiosnap Is making Sonar is double stretch during bounce but not playback? On my phone now: can provide more info later.

Huh.... I didn't think it was even possible to Ctrl+Stretch (AudioSnap) and apply a Region FX to a clip since both processes apply clip level changes.  Unless there are other suggestions, I would try bouncing the clip at 200% (offline algorithm) and then make your Melodyne edits to that version.
 

This is the brand new VST3 ARA implementation of Melodyne.  In Audiosnap properties the Audiosnap Enabled field is empty (not enabled) but the Enable Stretch (an Audiosnap settings checkbox) is available.  When Melodyne is the region FX, Sonar uses Melodyne's algorithms to perform the stretch.  It sounds good until I try to bounce to track or export audio. 
 
One issue I had with trying to follow Melodyne's instructions: the manual says that "Follow Host Tempo" needs to be selected in the region FX settings to perform time stretching, but when I select that option, Sonar won't let me Ctrl-Stretch a clip.  Maybe this is a clue.  But the first time I made the project this way, export worked fine.  I think things started going wrong when I copied the track to another track, but I'm not sure.  I didn't read anything in the manual about not being able to have multiple tracks each with region FXs on multiple clips.  I sent an email to Melodyne support to see if this is a known issue.

sorry, double post

Ah... I believe there is an issue in X3/ARA with copying "Melodyne'd" clips so perhaps that's a factor here.  I would keep each clip independent of each other if possible.
 

So I'm not going crazy. Good to know. Melodyne support told me to ugrade to Sonar X3e, which I didn't know existed. Will try tonight and follow up. Thanks!

Bingo!  Sonar X3e patch did the trick.  Trouble was, I upgraded from X3b to X3c a few weeks ago using Check for Upgrade.  There was nothing to indicate that there were two more upgrades available.  Every other program I use gives me the latest version when I check for update, or at least lists the patches I need and in in what order to install them to be up to date. :(.
 
The Melodyne manual is mistaken, though, in one regard: if Follow Host Tempo is selected, you can't Ctrl-Stretch the clip in Sonar, you have to change clip speed using tempo.
 
Thanks, stevec, for your help trying to solve the mystery.  Maybe this post will save someone time in the future.

Cool!   Glad you got it all figured out, and learned something along the way (X3e  :))
 
You should edit the subject as [Solved] so others can benefit should they come across something similar.