Diamond2 'End key' issue

[Guest n3ophile]

I have a weird issue with my Diamond2 (WM6.5), which just started happening this afternoon.

I have always had the phone set up such that a 2 second hold of the 'End' (hangup) key locks the phone. All of a sudden, it stopped doing this. The button itself is working fine and if I hold it down, it makes a small beep sound after 2 seconds as it always did. It's just, it doesn't do what it's supposed to. ;)

I've gone into the settings (Settings->All Settings->Personal->Buttons->End Key) and tried changing the function of the operation. No matter what I set it to, it doesn't do it.

I've tried a soft reset/removing battery, but it makes no difference. I'm trying to avoid a hard reset...

Anyone else come across this? Is it a Diamond2 issue? Or perhaps a 6.5 bug?

Cheers for any light you can shed.

Adam