Hi rbp, I don't if you have already solve the problem of the slowness of opening the url, but in the team I'm working, we have found a solution. The problem (and I don't know why) is that while you're working inside the environment of Qt (QtCreator) it took the 30-40 sec to open the browser and show the url. But, if you run the .exe of your appllication (avoiding first the problem of loading the dlls, ie. mingwm10.dll, QtCore4.dll, QtGui4.dll, etc.) The url problem disappears. So my advice is to you keep working and when you realease your app, you would have no delay problems.

Note: I have Windows Xp, QtCreator 2.0.0, Qt 4.7.0 (32 bits).