Hi Dave,
It looks like you have figured it out, but just in case:
You can remove models from Google Earth by unchecking the GE-ready
flag (which it appears you have already done); they'll disappear with
the next layer release, which takes about a week. Ordinarily, this
would also mean that the original block would come back, but since you
have also created a new model (this one, I presume?
http://sketchup.google.com/3dwarehouse/details?mid=ec09f2b899dc7f10d5c99c5c8c8e0b71)
it is entirely possible that your new model will get reviewed and
accepted instead. It's in the review queue now.
-- Allison