Open Windows displays nothing

I've been trying to follow the venkman tutorial as outlined @
http://www.svendtofte.com/code/learning_venkman/ I'm using the latest
venkman 0.9.79 and Mozilla Firebird 0.6. When I get to the part about
setting the context what I see in the open windows dialog is exactly
nothing. I've got a browser window open and the tutorial showing along
with the example file but none of these are displayed in the open
window dialog. Am I doing something wrong