Repeatable corrupting of bootloader (Nokia LCD)

Hi, I have been working with the Nokia 6100 LCD from sparkfun using the Nokia 6100 LCD Display Driver tutorial. I fidgeted with it a bit and using the provided functions, could draw lines, circles and rectangles. When I added the character display function, to Arduino got messy. The LEDpin(13) would blink rapidly and the Diecimila atmega168 chip was non-responsive. corrupted bootloader? I used the boot-cloner to bring it back to life then tried twice again (to check repeatability). Pre-character display worked fine but with the added functions, it froze up.

Any thoughts? I assume it is an incompatibility with the C code from the tutorial (which was written for an Olimex(?)). Thanks, Jeff

[edit]http://www.feesta.com/images/Nokia_LCD_problem.pde http://www.feesta.com/images/Nokia_LCD_working.pde [/edit]

sorry if the previous code was messy.

now working with it a bit more, I'm having trouble with other programs corrupting the bootloader. I've been working with Arduinos for a few months but don't know all the idiosyncrasies.

is it common for a sketch that corrupts the bootloader to be repeatable?

Are you reloading the bootloader?

Check the voltages on the Arduino. It sounds like something's been damaged. I wonder what voltage the Atmega168 is getting.

Thanks for responding. I will check the voltages. I've been powering with the USB and yes, I've been reloading the bootloader each time. I only have one Atmega168 with an Arduino bootloader right now.

In the past few days, I have been using the same chip for other programs. It was only when I had a very large array of bytes that the problem occurred. Could just be a coincident. I tried storing a 10kb image as bytes but now I just transfer the image over serial which is more practical. Could the memory be unstable for large objects? I don't know much about it but am having better luck by staying away from the unwieldy. Thanks!