Thanks for the help. I have this working now.

// def setupUi(self, qadashboard): etc..
QtCore.QObject.connect(self.comboBox, QtCore.SIGNAL(_fromUtf8("currentIndexChanged(int)" )), self.showMe)

// slot
def showMe(self):
self.index = self.comboBox.currentIndex()
if (self.index is 1):
self.checkBox_1.setEnabled(1)
self.checkBox_2.setEnabled(1)
self.checkBox_3.setDisabled(1)
self.checkBox_4.setDisabled(1)

elif (self.index is 2):
self.checkBox_3.setEnabled(1)
self.checkBox_4.setEnabled(1)
self.checkBox_1.setDisabled(1)
self.checkBox_2.setDisabled(1)

etc..

def retranslateUi(self, qadashboard):
I set everything to disabled in here.

So it all works as i'd like it to. Thanks for the help.