Unable to install rom on HTC Desire?

use xda-developers.com. they can help you with all of that. But stop using rom manager. It almost never works. To fix permissions go into clockwork recovery, choose advenced, then press fix permissions. To flash roms, go into clockwork recovery wipe data, cache, dalvik cache, and battery stats. mount your sd card and copy your rom from your computer to your sd card, select install zip from sd card, press choose zip from sd card. find your rom and flash away. DONT FORGET TO DO A NAND BACKUP!!!