Just to be sure that the .upgrade file is OK, what does md5sum give on the upgrade file (did you use the developer version or consumer?)

Here's what I have for md5sums (the developer I know work, as it's what I use)
639b4eeabce44d8932cb0efdcc1853b9 car2-consumer-v2.00-beta13.upgrade
f58d87146886657fda8d13dec1fc773e car2-developer-v2.00-beta13.upgrade


It might be also be something funky in the dynamic data partition - you might try nuking it, description here, but you may want to wait and see if anyones else offers other clues...

/Michael