I decided to try to mod my iPhone. However, I'm trying to follow the instructions on the iBrickr program and for some reason, can't start my iPhone in Restore Mode. The instructions say I should turn the phone off, turn it back on, and as soon as the grey Apple logo shows, press and hold the power and home buttons at the same time until a yellow triangle appears. However, when I do that, the phone just shuts off. Is there something I'm doing wrong?