The board is an Arduino Uno.
I replace stock Blink LED sketch with "Hello World" LCD sketch using Arduino 1.0. (Arduino wired to LCD as per instructions)
Observations:
The LCD sketch does not remain in memory when USB power is removed & replaced. It reverts back to Blink LED.
The LCD sketch does remain if I press the reset button on the UNO. (resets the timer on line 2 of LCD)
Any pointers for me? Thanks a lot.
Two possibilities...
Thanks Coding Badly,
Is the bootloader update due to corruption of the existing one?
Is the diode a replacement or board revision/mod?
Cheers
Andy
negativ3:
Is the bootloader update due to corruption of the existing one?
No. If the bootloader were corrupt you would not be able to upload.
There is a bug in an earlier version of the bootloader. What I remember is that on power-up the bootloader would corrupt the application area. But your board would have had to have been manufactured several months ago.
Details about the latest bootloader...
http://arduino.cc/forum/index.php/topic,64105.0.html
Is the diode a replacement or board revision/mod?
That's something you will have to decide. It is my understanding that folks have successfully modified their boards. But, it is also my understanding that the Arduino folks stand by their products which means you should be able to get it replaced if it has a problem.
Diode details...
I will upload the latest using ArduinoISP... 
That's something you will have to decide. It is my understanding that folks have successfully modified their boards. But, it is also my understanding that the Arduino folks stand by their products which means you should be able to get it replaced if it has a problem.
Diode details...
Arduino Forum
Now if there was instruction how to identify the "correct" polarity of the zener wrt ISP pins 5&6, that would be great. Google me thinks. Thanks for your help.