I'm having a serious problem with Qt 4.6.2 and Qt Creator 2 beta on Linux (haven't tested Windows yet, will do that tonight)

Text input periodically seems to switch off entirely, with no cursor shown and no input possible but selection still possible (as if everything has suddenly become read-only - although it happens to SpinBoxes as well as LineEdits/TextEdits)

Has anyone had a similar problem/knows of a solution? I'm not even sure whether it's a Linux/GNOME problem or a Qt one ...