I had the exact same problem with the new installer in b75a (upgrading on a real PC, not VMWare). It seems like there are some bugs in the new installer. I eventually ran the old installer to complete the upgrade, which was ugly but worked perfectly.
I tried the new installer several times, both with an upgrade and fresh install, and it crashed at the time zone or another early stage every time. You should be able to customize the partition sizes (on a fresh install) with the old installer, so I'm not sure why the sizes you're using are "wrong". I don't think that the new one lets you choose sizes at all (it just dumps everything to one partition.) This message posted from opensolaris.org
