windows - QToolButton setStyleSheet works on win8, not win7? -

the following works perfect on windows 8.1, not on windows 7. problem on win7 setstylesheet has no effect (compiled on 8.1 , deployed 7).

any explanations or workarounds?

qtoolbutton* button = findchild<qtoolbutton*>( qstring::number(buttonidx) );  button->setstylesheet("background-color: yellow; border-style: outset; border-width: 3px; border-radius: 5px; border-color: red; font: bold 10px; min-width: 1em; padding: 3px; "); 

problem upgraded earlier qt5.2 5.4. didn't include newer qt-dll's , platform in deployment.