please be aware of our compatibility list. http://www.celemony.com/cms/index.php?id=host_comp
Only Pro Tools 8.0.1 and higher are officially supported with Melodyne editor plugin RTAS. Use with previous versions of Pro Tools is on your own risk. jared1426 and davashmusic, which versions of Pro Tools are you running?
Regarding the crash and the track causing this: Are you able to import other tracks that contain Melodyne plugin instances successfully?
To nail down your problems, I ask you to write individually to support AT celemony DOT com, including the text of the crash report, that is displayed after the message that Pro Tools unexpectedly quit.
Please include your system details in the mail.