PortableUnixMailbox problem

[Gustaf Liljegren]

Guess I don't understand how to use it, but I get this error when trying to 
use the new (2.1) PortableUnixMailbox class:

E:\test>python pum.py
Traceback (most recent call last):
  File "pum.py", line 4, in ?
    m = mb.next()
  File "e:\python\lib\mailbox.py", line 19, in next
    self.fp.seek(self.seekp)
AttributeError: seek

And my code:

from mailbox import PortableUnixMailbox

mb = PortableUnixMailbox('in.mbx')
m = mb.next()

The problem appears on the line "m = mb.next()", where I try to create a 
rfc822.Message object from the mailbox.

Regards,

Gustaf Liljegren