diff --git a/direct/src/interval/Interval.py b/direct/src/interval/Interval.py
index 55df46bb85..f565672f07 100644
--- a/direct/src/interval/Interval.py
+++ b/direct/src/interval/Interval.py
@@ -20,6 +20,7 @@ class Interval(DirectObject):
         """
 	self.name = name
 	self.duration = duration
+	assert(t >= 0.0)
 	self.startTime = t0
 	self.type = type
 
@@ -38,6 +39,13 @@ class Interval(DirectObject):
 	"""
 	return self.startTime
 
+    def setStartTime(self, t, rel=PrevEndRelative):
+	""" setStartTime()
+	"""
+	assert(t >= 0.0)
+	self.startTime = t
+	self.type = rel
+
     def getType(self):
 	""" getType()
 	"""
diff --git a/direct/src/interval/IntervalTest.py b/direct/src/interval/IntervalTest.py
index ce483d9b3c..e3c09fe3c7 100644
--- a/direct/src/interval/IntervalTest.py
+++ b/direct/src/interval/IntervalTest.py
@@ -5,7 +5,7 @@ from IntervalGlobal import *
 import Mopath
 import IntervalPlayer
 
-AudioManager.spawnUpdate()
+#AudioManager.spawnUpdate()
 
 boat = loader.loadModel('models/directmodels/smiley')
 boat.reparentTo(render)
@@ -13,24 +13,29 @@ boat.reparentTo(render)
 dock = loader.loadModel('models/directmodels/smiley')
 dock.reparentTo(render)
 
+sound = loader.loadSound('phase_6/audio/sfx/SZ_DD_waterlap.mp3')
+
 mp = Mopath.Mopath()
 mp.loadFile(Filename('phase_6/paths/dd-e-w'))
 
 boatMopath = MopathInterval('boatpath', mp, boat)
 
-sound = loader.loadSound('phase_6/audio/sfx/SZ_DD_waterlap.mp3')
-waterSound = SoundInterval('watersound', sound)
+boatTrack = Track.Track([boatMopath], 'boattrack')
 
+# Make the dock lerp up so that it's up when the boat reaches the end of
+# its mopath
 pos = Point3(0, 0, -5)
 hpr = Vec3(0, 0, 0)
 dockLerp = LerpPosHprInterval('lerp', dock, pos, hpr, 5.0)
+dockUpTime = boatTrack.getTrackRelativeEndTime('boatpath') - dockLerp.getDuration()
+dockLerp.setStartTime(dockUpTime, Interval.Interval.TrackStartRelative)
+dockTrack = Track.Track([dockLerp], 'docktrack')
 
-boatTrack = Track.Track([boatMopath], 'boattrack')
-dockWaitTime = boatMopath.getDuration() - dockLerp.getDuration()
-dockTrack = Track.Track([Wait(dockWaitTime), dockLerp], 'docktrack')
-postSoundWaitTime = 3.0
-preSoundWaitTime = boatMopath.getDuration() - (waterSound.getDuration() + postSoundWaitTime)
-soundTrack = Track.Track([Wait(preSoundWaitTime), waterSound, Wait(postSoundWaitTime)], 'soundtrack')
+# Start the water sound 5 seconds after the boat starts moving
+waterStartTime = boatTrack.getTrackRelativeStartTime('boatpath') + 5.0
+waterSound = SoundInterval('watersound', sound, loop=1)
+waterSound.setStartTime(waterStartTime, Interval.Interval.TrackStartRelative)
+soundTrack = Track.Track([waterSound], 'soundtrack')
 
 mtrack = MultiTrack.MultiTrack([boatTrack, dockTrack, soundTrack])
 
diff --git a/direct/src/interval/SoundInterval.py b/direct/src/interval/SoundInterval.py
index 509ecc5e5a..80bcca7d50 100644
--- a/direct/src/interval/SoundInterval.py
+++ b/direct/src/interval/SoundInterval.py
@@ -16,6 +16,10 @@ class SoundInterval(Interval.Interval):
 	self.name = name
 	self.sound = sound
 	self.duration = self.sound.length() 
+	if (self.duration == 0.0):
+	    Interval.Interval.notify.warning(
+		'SoundInterval(): zero length sound - setting duration = 1.0')
+	self.duration = 1.0
 	self.loop = loop
 	self.isPlaying = 0
 	self.startTime = t0
@@ -25,8 +29,9 @@ class SoundInterval(Interval.Interval):
 	""" setT(t)
 	    Go to time t
 	"""
-	print 'SoundInterval.setT(): t: %f' % t
 	if (t > self.duration):
+	    if (self.isPlaying == 1):
+		AudioManager.stop(self.sound)
 	    return
 	assert(t >= 0)
 	if (t == 0):
diff --git a/direct/src/interval/Track.py b/direct/src/interval/Track.py
index d460ca4df2..e7bac550b1 100644
--- a/direct/src/interval/Track.py
+++ b/direct/src/interval/Track.py
@@ -56,7 +56,7 @@ class Track(Interval.Interval):
 	"""
 	for i in range(len(self.ilist)):
 	    if (self.ilist[i].getName() == name):	
-		return self.__computeDuration(i) - self.ilist[i].getDuration()
+		return self.__computeDuration(i+1) - self.ilist[i].getDuration()
 	Interval.notify.warning(
 		'Track.getRelativeStartTime(): no Interval named: %s' % name)
 	return 0.0
@@ -72,7 +72,7 @@ class Track(Interval.Interval):
 	"""
 	for i in range(len(self.ilist)):
 	    if (self.ilist[i].getName() == name):	
-		return self.__computeDuration(i)
+		return self.__computeDuration(i+1)
 	Interval.notify.warning(
 		'Track.getRelativeEndTime(): no Interval named: %s' % name)
 	return 0.0
@@ -88,11 +88,9 @@ class Track(Interval.Interval):
 	    # Anything beyond the end of the track is assumed to be the 
 	    # final state of the last Interval on the track
 	    self.ilist[len(self.ilist)-1].setT(t)
-	    print self.name + ': t > self.duration'
 	else:
 	    # Find out which Interval applies
 	    prev = None
-	    print self.name
 	    for i in self.ilist:
 		# Calculate the track relative start time for the interval
 		t0 = self.__getTrackRelativeStartTime(i)
@@ -100,7 +98,6 @@ class Track(Interval.Interval):
 		# Determine if the Interval is applicable
 		if (t < t0):
 		    if (prev != None):
-			print 'in a gap at t: %f' % t
 			# Gaps between Intervals take the final state of
 			# the previous Interval
 			prev.setT(t)
@@ -110,8 +107,6 @@ class Track(Interval.Interval):
 				'Track.setT(): state undefined at t: %f' % t)
 			return
 		elif (t0 <= t) and (t <= t0 + i.getDuration()):
-		    print 'in interval: ' + i.getName() + ' at t: %f' % t
 		    i.setT(t - t0)
 		    return
 		prev = i
-	    print 'no intervals apply at t: %f' % t