Qt 5.2 c++ model update stops working after a while

Hi everyone, I have an App, that works under Qt 5.1 (Windows), where I update a c++ model quite often, and show the result in two nested ListViews. But under Qt 5.2, after a few seconds the ListViews stop showing the changes of the model. When I slow down the update rate, it works longer, but after a while also stops working. I can’t see any errors or warnings. Has something changed in Qt 5.2, that I should be aware of, or can this be a bug? Thanks