So if I understand you correctly, you just had the I2C address wrong on the HMC? Or did introducing a delay, having the "beginTransmission" immediatly followed by the "requestFrom", etc - make any difference. I'm wondering if you got your 24LC256 working or not as well. I am fairly certain I have the correct address using the Wire lib, yet I'm not getting it to work. If you could hook yours up and scope if it does not work - I would really appreciate it.
Congrats on getting your HMC working!
-- Josh