Our #1 pitivi bug on ubuntu 10.04 seems to be due to something misbehaving in pycairo.
This worked without any problems on Ubuntu 9.10 and some other distros, but it seems that distros with more recent versions of pycairo are affected. Any help in fixing this/figuring out what's going on would be much appreciated!
pycairo is not the upstream package for this bug, pygtk is (and pycairo is upstream for pygtk).
cr.reset_clip() is calling gtk.gdk.CairoContext.reset_clip.
This is a pygtk function not a pycairo function.
Philippe Gauthier has already successfully diagnosed the problem, on BOTH the bug reports you quote, as being pygtk and not pycairo. Why do you ignore his advice?.
I suggest you open a bug report for pygtk.
Sorry, his comments arrived at roughly the same time that I was filing this bug, so I hadn't seen them and I wasn't sure what was causing it, so I needed your input.