[pygtk] Interoperability with Boost.Python-generated extensions

[Jonathan Brandmeyer]

I want to create a new class that logically should have an "is-a"
relationship with a gtk.DrawingArea and a Boost.Python-generated class. 
So, I tried to create a new class that inherited from both, but got a 

"TypeError: multiple bases have instance lay-out conflict"

It turns out that any class that inherits (directly or indirectly) from
gobject.GObject and any Boost.Python-generated class will produce this
exception.

Why would this happen?  Is this a known issue, and is there a workaround
for it?

Thanks,
-Jonathan Brandmeyer