If this is an intermitten fault on setting the program then it can only be down to the control board. As for you not being able to select a cycle and then somtimes you can do then its can only be an electronic control board fault here.
If you remove the outer door panel there you will see the control board. You will need to replace this to cure the fault to sort this out. But this isnt going to be a cheap fix as control boards on these are over the £100 mark.
Sorry its not looking like good news but if you need anymore info just get back to me.