I am wondering if there are any know issues with the
i2c header J22 on the main board.

I wired in a Microchip 24LC256 eeprom and ran
i2cdetect 0 in Linux and did not see the part at
address 0x04 where I expected. I did see the rtc part
at address 0x32.

I was able to run i2cdump 0 0x32 and see the rtc
registers without the 24LC256 wired in. I then tried
to run i2cdump 0 0x32 with the 24LC256 wired in to
J22, with no power, and now i2cdump 0 0x32 hangs, with
or without the 24LC256 wired in at all. I wonder if the rtc is
corrupted now...

I should be able to at least see the 24LC256 part show
up at the wired in address of 0x04, even without a
specific driver installed.

Thanks,
Tom