Melodyne Doesn't Bounce

If I understand correctly, you have the Melodyne plugin in the effects bin and you want to bounce/render it so the effect is applied permanently?
 
If that is correct, the only way I've been able to permanently render Melodyne to a track is not to bounce it - either in the same track or to another track (though exporting to another track may work) is to select the track with Melodyne in the FX bin and select "Apply Effects" from the "Process" menu. 
 
This will render and apply Melodyne to the track and delete the Melodyne plugin (by default, but there is an option to keep it there, which wouldn't really make sense for Melodyne).  You're left with an audio track with Melodyne applied and an empty FX bin.
 
If you want to keep a copy of the untreated track, simply clone it before applying Melodyne.
 
Also, if you want apply additional effects other than Melodyne, remove them from the bin before processing FX, otherwise all of the effects will be permanently applied as well (unless you're 100% sure you have the sound you want).
 
Generally, I try to use Melodyne first to correct any issues, apply FX, and then insert additional plugs to the rendered track as needed.  Also note that when capturing (and rendering, I would assume), your audio buffer has to be set at 1024.  Once rendered and the plugin is gone, you can switch back to any buffer size.
 
Hope this answers your question or at least helps.