During upgrade, schema_migrations table not populated

We upgraded our app from Rails 1.2 to 2.3. There were no outstanding
database
migrations, i.e. the database was up-to-date during the
upgrade/deployment
process. The schema_migrations table was created, but it was not
populated and
the schema_info table was not removed. Can anyone explain why the new
schema_migrations table would be created but the data from the
schema_info
table not used to insert values into it? Everything I've read about the
upgrade process says the schema_info table would automatically be
replaced
with the schema_migrations table; does this not include actually
populating
the new table??