AF360 Query comparing it to AF540 - possible issues?

Hi
I have both of these - the AF360 being almost brand new. Comparing the two against each other I find...

The green backlight is MUCH dimmer on the 360. On the 540 it is really bright. Anyone else noticed this?

On the 360 the "ready/test" button is very hard to press. I cannot press it with my thumb as no matter how hard I press it I cannot depress it enough. I have to use the end of my thumbnail. Surely this cannot be right? I don't even have big hands either!

Any thoughts?

I found much the same. I haven't got the 360's any more.