Qt4 slow like molasses

[Tommytrojan]

Hi,

I'm in the process of porting an app from Qt3 to Qt4. I have a moderately complex dialog with one list view (QTreeWidget) which is basically empty (it has two items in there) and a handful of buttons. See the two attachments for the Qt3 and Qt4 dialog screenshots.
In Qt3 resizing the dialog is is really snappy like you would expect from a normal dialog. In Qt4 however, the resize operation is so slow that the buttons seem to 'jump out of the dialog'. They seem to have some kind of momentum and the entire dialog looks distorted. What am I doing wrong. This can't be the normal performance of Qt4, this would not be usable as a commercial application. Any ideas?


Thomas