Symbian: Connecting to network causes QML application framerate to drop considerably

Restart QML Viewer to make sure the application hasn't yet connected to network. Run attached qml example with Symbian^3 device. Look at the animated rectangle, which x and y position is being continuously animated across the screen. After 3 seconds of creating the view QML code asks Qt to fetch a small image over network. When network access manager is created the frame duration of the animation drops momentarily from around 13-21 ms per frame to well over a second (1646ms) and few frames later drops again twice to over 100ms per frame (113ms and 169ms frames). The image is fairly small and the same lag happens with networked XmlListModel, so the lag does not seem to be caused by QML, but by Qt networking.

This is an important issue to fix, because

• most non-trivial mobile applications are networked, and most of those applications will momentarily become unresponsive when the network is initiated
• many QML-based applications use animations and transitions for smoother visual experience, any running animations will halt for over a second when the network connection is being established
• good mobile application user experience requires the interface to remain responsive even during heavy load