QScroller scrolling is weird when scrolling occurs diagonally

I'm using QtScroller (the "solution" branch from http://qt.gitorious.org/qt-labs/kineticscroller), which I understand is what is used in Qt 5.0, and I noticed a weird behaviour when scrolling occurs in both directions: the scrolling movement doesn't occur along a straight line.
Instead, QtScroller independently scrolls the X and Y coordinates, with the effect that it's possible that scrolling in one direction ends before the scrolling in the other one; so, you'll see that the scrolling occurs diagonally for a while, and then continues along the X or Y axis only.

QtScroller should just use one single dimension for scrolling, and project it to the X and Y axis when needed.