8.0 -> 8.1 migration issue with ROLEs ... maybe?

I just setup a test 8.1 server, to see how things work as far as the new
roles system is concerned, as it relates to migrating from 8.0->8.1 ...
specifically since there doesn't appear to be anything in HISTORY
concerning migrating up to 8.1 from 8.0 concerning this ...

As expected:

template1=# create group a_test_group;
CREATE ROLE
template1=# create user a_test_user in group a_test_group;
CREATE ROLE
template1=#

but:

template1=# create user a_test_group in group a_test_group;
ERROR: role "a_test_group" already exists
template1=#

So, if I have a group that happens to have a userid matching it, in the
old system, its going to fail to load?

Whereas, under 8.0, it does work:

test=# create user a_test_group in group a_test_group;
CREATE USER
test=#

Is there something I'm missing here, as far as ensuring a 'clean'
migration from pre-ROLEs?

----
Marc G. Fournier Hub.Org Networking Services (http://www.hub.org)
Email: scrappy(at)hub(dot)org Yahoo!: yscrappy ICQ: 7615664