Problem with events and window resizing

I have some code that's been working for a long time, but it's behaving strange
with current (svn) matplotlib. It's too large to post here, so I will try to
come up with a minimal version reproducing the problem. Meanwhile, I wanted to
ask if anyone would have a clue of what could be going on. The symptoms are that
the interaction (keys and mouse clicks) works OK as long as I don't resize the
window. Once I do this, the interaction is gone. What happens when the window is
resized, that could be related to what I experience.

OK, lets see if I can come up with a simple code reproducing this...