reom_76

I'm having trouble flashing a ROM (shooting for CM7) for the first time. I've downloaded the CM7 zip to my sd card and gone through ROM Manager to Flash ROM from SD card, but when my phone boots into recovery, it can't complete the installation. Here's what I'm getting

Update media, please wait
update media, finished

--Install from package...
finding update package...
verifying update package...
(in red letters) E: failed to verify whole-file signature
(in red) E: Signature verification failed

--appling muti-csc...
installing multi-csc
(in red) installation aborted.

I feel like I need to start the wiki tutorial from scratch, but when I try to retrace the steps through ROM manager, but it's giving that same issue. When I start by Flashing the ClockworkMod Recovery, it tells me "ROM Manager has been set up to use your existing recovery installation. I'm guessing it is recognizing the one I flashed the firs time around. If I choose to download ROM from the ROM manager and choose CM7, it recognizes that I've already downloaded it. I then choose to wipe cache and whatnot and click OK to complete the install and the phone reboots and gives me the same error as above.

Basically, I think I've screwed something up somewhere. Is there something I can do to start over. I don't really want to have to flash back to a stock ROM and lose everything. I'm hoping there's something in between. Can I somehow clear the clockwork recoverymod and start again? Thanks again for all the help.