Possible bugreport 8.3 beta1 on Win32: Looking like a deadlock with AutoVacuum

OS: Windows XP Pro SP2
CPU: AMD Athlon 64 3500+
RAM: 2GB
DB: PostgreSQL 8.3beta1, compiled by Visual C++ build 1400

I've come to the conclusion that it seems like a deadlock occurs when 
dropping a column in a table the same moment that table is autovacuumed.

Example:

ALTER TABLE bondetail DROP COLUMN btw; (user=gino, 16252 records)
deadlocks with
VACUUM ANALYZE public.bondetail; (user=postgres)

If you wait a very long time, it goes on, the quick method is to cancel 
the VACUUM command.
If you need some more info, let me know.

Greetings
Deblauwe Gino