Why are there songs being played inside a scheduled playlist that aren't in the playlist?

For instance for all of our specialty shows, we will set up a playlist as follows:

Type:  Scheduled
Scheduled date:  8/12/2015
Scheduled time:  8:00 PM
Repeat Schedule:  Weekly
Repeat on:  Wednesday
Playback Style:  Play All Tracks Sequentially (In Order)
Interruptible:  No, always play to completion or stop time
Stop After:  0

The playlist is then loaded with media as follows:

Segment 1 (30:00)
Segment 2 (30:00)
Segment 3 (30:00)
Segment 4 (30:00)

Now, with the above settings, we assume the show will air every Wednesday starting today at 8:00PM, that each of the segments in the playlist will play sequentially without interruption (in this case for 2 hours) then when completed (all segments have been played completely) the system will then immediately play the next scheduled program (Same setup only to begin at 10:00 PM) or resume a rotation playlist if no other shows are set to begin at 10:00 PM.

What really happens is this:

8:00 PM Segment 1 plays (30:00)
8:30 PM A fill song plays from the library or some other playlist
8:34 PM (or thereabout) Segment 2 plays (30:00)
9:04 PM (or thereabout) A fill song plays
9:08 PM (or thereabout) Segment 3 plays  (30:00)
9:30 PM (or thereabout) A fill song plays
9:42 PM (or thereabout) Segment 4 plays (30:00)
10:20 PM (or thereabout) A fill song plays
10:24 PM (or thereabout) The next show starts

As you can see it not only plays songs we don't want played during specialty programming, but it also throws the entire clock off for the night.

Please advise - it seems that a setting "Interruptible:   No, always play to completion or stop time" and "Stop after:    0 Minutes  (0 to play to completion)" should prevent anything else from playing inside these schedules. 

Thanks!

It appears that Liquidsoap is sometimes miscalculating the length of the track it is playing and it's contacting Centova Cast (pre-emptively, before the current track even finishes playing) to ask for the next track.

This is what leads up to an additional song being played between playlists.

While this seems to be a Liquidsoap bug, we are also looking for a workaround for this issue