Qtoolbar button and checked state is not shown

The checked state is not shown in Qtoolbar Action Icon.
It works on all win and mac platforms.

The debuggable code
----------------------------------------------
int checked;
if(g_ULdata->frames[g_ULdata->ActiveFrame].CenterOnShip){
checked=true;
}
else{
checked=false;
}
int checkednow=ui->actionKeskit->isChecked();
if( checkednow!=checked){
ui->actionKeskit->setChecked(checked);
}
--------------------------------------------------------------------------------
Has no effect on shown apllication??

This works if application tstyle is set to QWindowsStyle