if you removed the firmware you must update the Zune with the latest firmware before trying to add any media.
did you reinstalled the firmware ?
Okay - here's what I did... I reset the firmware on my Zune, it said "plug into computer" (or whatever) and I followed all of the steps. Then, my Zune said "complete" or whatever, but my computer did not. I let it sit for nearly 20 mins and nothing was happening w/ the computer software. So... I unplugged. I did not get an error on either side. So, I plugged my Zune back in to sync it. It got to 13%, then froze - the computer said "Zune is disconnected" or something of the sorts. And, now, it just won't work. I kept trying to sync it throughout the day, and it wasn't even recognizing that the Zune was plugged in. Now, it'll recognize the Zune, but it won't sync my files. It keeps popping up w/ a Read Error. It says "The Zune software can't access important data on your Zune. Try disconnecting and reconnecting it. If the problem persists, contact customer support."