Comment 5 for bug 954312

Right, it's actually not an ubiquity bug, marking as Invalid.

You can't use gobject or gst in an ubiquity plugin because they won't mix with pygi.
Instead you should use "from gi.repository import Gst, Gobject" or something along those lines.

Also, PageGtk should only be doing the initialisation of the UI, not run anything at this point.
You should instead move the code actually starting the video and doing the toggle_top_level to the Prepare() function of the "Page" class.

self.page of PageGtk also needs to be set to the UI of your step or it'll be skipped.

I tend to use ubi-prepare.py as an example for other steps.