bugfix to prement AV.
bugfix to prement AV.

The ComboBox.Checked property now fires the event even when set programmatically.
So we better set the event handler AFTER we set the Checked property. This is
how it is done in all other components anyway.

wkitty42/fpGUI,wkitty42/fpGUI,wkitty42/fpGUI,wkitty42/fpGUI,wkitty42/fpGUI,wkitty42/fpGUI