[Twisted-Python] twisted + wx + pypubsub = progress bar update problem

Hello everyone, I am using wx (wxreactor) and pypubsub with twisted and I'm having some issues. I have a loop that updates values and I'm trying to show the user the progress. The loop uses pypubsub to update the progress bar but even if I explicitly refrech the progress bar widget it doesn't do it until the loop exits. I tried calling ProcessPendingEvents() but it doesn't solve the problem. Does anyone have an idea on how to solve this? Thank you, Gabriel