I just tried to use bsddb with the source argument to have
flat 
backing file. Creating a database with such a backing
file as 
source was not problematic, but after I had modified
it, the 
sync() and close() method would hang.

For 
example:

from bsddb import rnopen
r = 
rnopen('test.dat', source='test.txt')
r[1] = 'foobar'
r.sync() 
# Hangs here...

After running this, test.txt will be empty 
(even though it
wasn't before). Running the code above without 
the source
argument works just fine.

I'm running 
Python 2.3 cvs version (slightly earlier than the
first alpha) on 
SunOS 5.9.