Importing a large AVI file causes the file to be negatively loaded

Importing a large AVI file causes the file to be negatively loaded, as in, it's displayed as loading at -30000% and the number grows. Once it's done loading, the user is left with an empty rectangle that is always the same size no matter the large AVI imported and can be dragged around but can't be played. See screenshot below if this is still not clear.

Steps to Reproduce:
1. Start Jokosher and open a new project
2. Add an instrument
3. Import a large AVI in the instrument track

This is printed on the terminal when the bug occurs:
/home/redfox/Software/jokosher/trunk/Jokosher/Event.py:102: Warning: value "-1" of type `gint64' is invalid or out of range for property `duration' of type `gint64' self.filesrc.set_property("duration", long(self.duration * gst.SECOND))

Expected Result:
For the audio of the AVI to be imported, like it does for smaller AVIs.

System Information,
Software:
Ubuntu Edgy (6.10)
Recent build of GStreamer from CVS
Latest version of Jokosher from Subversion

Hardware:
Asus A7N8X Deluxe
2 soundcards, onboard NVidia nForce2 soundcard (main one), Ensoniq AudioPCI (secondary)