this is how ive hacked my old x8, you havent unzipped the file before saving it to your sd card have you? it needs the whole bundle.
it can be a wee bit of a pain and also i have discovered that most hacked os's fail in some way and it took a few versions before i was completely happy with the funcionality of my phone.
as mike says xda developers are your boys.
x8 e15i on android v 2.3 gingerbread rooted with linux kernel, and overclocked to 860hz
dunno if this helps.
