QPushButton containing images are not displayed correctly in Maemo

A couple of screenshot is better than thousand words. Please give a look at this application I'm building, running on a N900 (of course with latest PR 1.2 installed): http://a.imageshack.us/img194/3969/screenshot2010071417591.png
and look the same UI running on desktop: http://a.imageshack.us/img822/9967/lastgodesktop.jpg

As you can see the images/buttons on Maemo are not displayed correctly. If I remember well this was a known bug and should have already been fixed, but it's not as you can see.

Please let me know if there is any workaround available or if you're able to fix this in short time.

Thanks.