Comments referring to your webpage on AVR:
Only true for 40-pin Mega16 and Mega32 but Mega8 has only 28-pins so will come with less I/O pins available.
Even with a 1MHz crystal one will not get exactly 0.266144 second, albeit with an internal RC oscillator. Just stick with 0.26 second.
Are you sure you're not looking at old webpage material on the web? I checked the avr-libc that comes with WinAVR and this is what I have found.
"Presently supported are two locations of the EEPROM register set: 0x1F,0x20,0x21 and 0x1C,0x1D,0x1E (see __EEPROM_REG_LOCATIONS__)".
Mega48/88/168 eeprom registers are located at 0x1F,0x20 and 0x21.
avr-libc eeprom declarations