... have a chance of finding the bug when a mile of code is involved. As Jon and Andy suggest "you need to start by writing a simple application that just reads and writes the EEPROM. Once you have that working, you can move on to integrating it with the rest of your code."

I have so often seen, as a result of "the code must be finished when the hardware arrives" that "a mile" of code is malfunctioning and everybody run all over trying to find the needle in the haystack. You need to make the haystack smaller to have a chance of finding the needle.

The only way I know of making working code is to make small parts, make them work, and then include them. OK, there is, of course, also luck.

one word of advice: you have done a "reasonable" job regarding comments, do a "great" job instead. Often a bug can be found by simply commenting the buggy area.

Erik