Radio Button delay problem

I’ve set up a matrix of three buttons
when project is built to run as an app two simular (minor) problems appear
when the the window with the buttons is opened, two buttons appear to be selected,
but the correct button is active. If you select a button in the matrix it clears all the other buttons
except for the one selected.
the other simular problem is when a different button is choosen there is a second or two delay when both
(old and new buttons) appear selected.
anybody had this problem, or is it just my poor scripting technique
Any suggestions.