Pressdelay of Listview has no effect when flicked

I use a touchscreen with tslib.

The attached example contains a listview with buttons having a mousearea.
The pressdelay works fine when the button is pressed only.
But the "pressed" signal is delivered immediately when I press and then flick.

The documentation of pressdelay says:
If the flickable is dragged/flicked before the delay times out the press event will not be delivered