Another way is to refresh your Xseq file. This will clean out any artifacts that might have been created. To do this make a copy of your xml sequence fil.
Example
Wizards,MP3
Wizards.lms
Wizards.xseq
Wizards.xml
Delete or rename Wizards.xseq
Now create a new sequence from a sound file (3rd option of open)
Use Wizards.mp3 as the sound file.
Now press save and a new Wizards.xseq is created without the artifacts. When u press save it will use the existing Wizards.xml file.