Sorry, but that's not the case. It is really named just "update.zip" the fine passes the verification, but fails on verifying the existing OS.
If you don't believe me, heres the ls output of my SD card.
Code:
adam@Daedalus/Volumes/DROID: ls
20091124091334124.pdf download
DCIM google_maps_navigation
Droid.icns greed
Images media
LOST.DIR mnn
MarkSpace prettyweather-googlecode-com
adobe screenshot1258950909189.png
albumthumbs tmp
amazonmp3 twc-cache
cardiotrainer twidgit
com.google.android.apps.listen [COLOR=Red]update.zip[/COLOR]
data