[kelnage]

That is likely the correct answer. I believe the problem is the machines use a resistive touch screen (which respond to pressure - and hence the finger nail is more effective) as opposed to the capacitive touch screens that pretty much everyone else has adopted.

[ninjamayo]

Not sure if that is the case. I have tried everything so far, fingers, nails and the only way is to direct your finger at an angle. These are not the same machines with the ones in Paddington, Victoria, etc. They are brand new and very unresponsive.