I definitely had (have) twentyten in my themes directory. assuming everything else went well, is there any reason to think it wouldn’t have seen the theme?
for what it’s worth, i tried to change the install to a subdirectory network, but that gave the same result — wp-admin was accessible, but the new site wasn’t (even as a subdomain). i just reverted back to a pre-network setup, and erased the tables that multisite added to my install.
come to think of it, when i switched to a subdirectory instead of a subdomain setup, i never undid the first, just changed the values in wp-config.php. any reason to think that if i give it one more try, going straight to subdirectories, it might work the third time?
thanks.