OK thanks

What is the usb socket in the middle of the powered cradle for?
Anyone know?

I have a zumo 400 been reliable for years, but since the last update it has had a couple of issues,

Fuel gauge does not work
occasionally top half of the screen inverts
any thing over 80 mph and it showed max speed of 256 mph
I could live with this.

But now I had an issue with the buttons on the ...