Power-saving standby mode Navman S90i not working

[sharpis]

Q1.) Unit not turning on after automatically shutting off!
Ref: Page 14 Power (English - Australian Manual).
It turns on OK with a momentary press of the power button,
Screen then shows screen saver window with buttons OK and Cancel for about 2secs and then turns off again.
The only way to turn unit on again is by holding down the power switch for 2 to 10secs, release, wait a few secs and then hold power button again for about 2-5secs.
(ie. a full reboot).
If I leave it to power off by itself with charger connected or disconnected (it doesn't matter which),
then when I unplug the charger, if it's plugged in, and then plug the charger back in again, it will automatically turn on.
ie. Come out of automatic shut off mode OK and stay on.
What's causing this?

Q2.) Power-saving standby mode not working!
Ref: Page 14 Power (English - Australian Manual).
It turns off OK with a momentary press of the power button,
Subsequent momentary presses of the power button again (10~20secs apart make no difference) and device will not wake up.
What's causing this?

On both problems - Not setting a security pin it doesn't work either.
I sent it away to Navman for repairs and all software was re-imaged.
It's still doing exactly the same thing.

Do all Navman S90i's behave like this? S80's? etc.

Other Notes:
Page 88 Power (English - Australian Manual).
Settings for Power, Turn off automatically
- on battery power 3mins
- on external power 3mins

Page 13 How do I monitor the battery status (English - Australian Manual).
Fully charged should last 3 hours (Typo in Brochure 5hrs?).

[sharpis]

Solved
2008-11-10mon Sent my Navman S90i GPS back a 2nd time to Navman Service and the Main Printed Circuit Board was replaced.

2008-11-21fri Received GPS back after repairs.
All problems above have been fixed.

Cheers Sharpy