Exactly the same symptoms here:
Did the OTA download - downloaded the whole file, then it reported "can not verify". Tried three times, same (non)result each time.
Tried the local update, and at the bottom of the list was "ota.zip" - selected this, and it went through the motions of verifying the package, and started the install. When it rebooted, I got a "Dead Android" icon - not a good sign!
Did a manual re-boot, and it went back to where I was before (Android 4.0.3 Baseband Version 1.2rcOTA), so no damage done - phew!
Can anyone confirm whether they have successfully done an update of the Vi40 Elite using either method? I'm happy to wait a week or two for an official Onda "fix" before I take the plunge with flashing to CM9.