Need some help.  I'm new to installing ROMs.  I installed the Blue Steel Room to check it out, and now I want to check out the Liberty ROM.  I'm using ROM Manager Premium From ClockworkMod.  Now when I try to flash a new ROM, using the "Install ROM from SD Card" the system reboots as if it will install ROM but just reboots all the way with out actually installing ROM.  I don't know why it is not working now, and I don't know what to do to get it working again.  I have done several Factory Resets and reinstall of the app, but nothing seems to work.  I would like to try several ROMS maybe even some Beta or Alpha ROMs, so I don't want to get stuck with a ROM one it is installed.  I know many people switch ROMs all the time, so I know that I should be able to do it with ClockworkMod ROM Manager.  Could somebody please give me some advice and tell me what I might be doing wrong, and how to do it right, and better for the future.  Please remember I'm new to this.