I found a bug in my K618i
I am using the latest firmware R1ED001.
Whenever I press 6 and 9 together (press at the same time), my phone will shutdown.
This happens 8 out of 10 time whenever I try it.

Just want to know if other K618i users having the same problem.

Have you tried pressing other combination of keypad, like (1and2), (2and3)... etc
To my experience, 6+9 is the most frequent to have problem.

Regarding your shortcut problem, I used to have that problem also.
Everytime after I use the cable to transfer file, the navigation shortcut is gone!

My way to solve it is:
1)Set your Navigation key shortcut
2)Manually shutdown your phone
3)Restart your phone
After this, your navigation shortcut should be permanently saved.

Does anyone knows where to get K618 screen protector?
I have been searching everywhere, but many shops do not have it.

Notice any improvement made?

Successfully update to R1GB001.
Notice the menu animation. Cool.

I used to have the "auto-off" problem. On top of that, I also have the earpiece (cann't hear others talk) problem. I've tried updating firmware but the problems still persist.
One day, I sent it back to my AP service center, all problem fixed.
The technician said nothing wrong with the phone, and he just "wipe" the connector inside the phone clean. Surprise?!
No problem ever since. My K618 is 1 year old now.