Got this crash with butterfly 0.5.0 and papyon 0.4.1

DEBUG:Transport:<<< UBX lbigonville@passport.com 1 331
	[payload]
INFO:Butterfly.Aliasing:Contact <ButterflyContactHandle id=94 name='lbigonville@passport.com#1'> alias changed to 'Bigon [MSN]'
DEBUG:Transport:<<< MSG Hotmail Hotmail
	MIME-Version: 1.0\r\n
	Content-Type: text/x-msmsgsinitialmdatanotification; charset=UTF-8\r\n
	\r\n
	Mail-Data: <MD><E><I>103</I><IU>93</IU><O>4</O><OU>2</OU></E><Q><QTM>409600</QTM><QNM>204800</QNM></Q><M><T>11</T><S>7</S><RT>2009-08-08T08:08:22.790Z</RT><RS>0</RS><SZ>1470</SZ><E>vivelesguidesdemarche@hotmail.com</E><I>9F18B355-46EB-4A2B-AF76-1479D39D923F</I><F>00000000-0000-0000-0000-000000000009</F><N>=?utf-8?B?dml2ZWxlc2d1aWRlc2RlbWFyY2hl?=</N></M><M><T>11</T><S>7</S><RT>2009-08-23T12:05:47.220Z</RT><RS>0</RS><SZ>1310</SZ><E>carole_dao@hotmail.com</E><I>766416DF-B1F2-48AD-9C01-1FAC58866DD2</I><F>00000000-0000-0000-0000-000000000009</F><N>=?utf-8?B?Y2Fyb2xlX2Rhbw==?=</N></M><M><T>11</T><S>7</S><RT>2009-08-26T08:06:19.513Z</RT><RS>0</RS><SZ>1395</SZ><E>vivelesguidesdemarche@hotmail.com</E><I>AB9345EE-F5D9-4C3C-B2FA-9161C5C60599</I><F>00000000-0000-0000-0000-000000000009</F><N>=?utf-8?B?dml2ZWxlc2d1aWRlc2RlbWFyY2hl?=</N></M><M><T>11</T><S>7</S><RT>2009-08-28T12:07:34.797Z</RT><RS>0</RS><SZ>1378</SZ><E>vivelesguidesdemarche@hotmail.com</E><I>BEAA8C21-FFC3-49D8-84D1-62ABDBFF7EE0</I><F>00000000-0000-0000-0000-000000000009</F><N>=?utf-8?B?dml2ZWxlc2d1aWRlc2RlbWFyY2hl?=</N></M><M><T>11</T><S>7</S><RT>2009-09-02T11:58:52.313Z</RT><RS>0</RS><SZ>1404</SZ><E>carole_dao@hotmail.com</E><I>1BC7309D-266E-452A-A9C5-A4CD78F5CB1C</I><F>00000000-0000-0000-0000-000000000009</F><N>=?utf-8?B?Y2Fyb2xlX2Rhbw==?=</N></M><M><T>11</T><S>7</S><RT>2009-09-12T07:46:52.920Z</RT><RS>0</RS><SZ>1281</SZ><E>vivelesguidesdemarche@hotmail.com</E><I>41A5E0D9-D107-4AC2-B8CA-2EC46BDFDD6C</I><F>00000000-0000-0000-0000-000000000009</F><N>=?utf-8?B?dml2ZWxlc2d1aWRlc2RlbWFyY2hl?=</N></M></MD>\r\n
	Inbox-URL: /cgi-bin/HoTMaiL\r\n
	Folders-URL: /cgi-bin/folders\r\n
	Post-URL: http://www.hotmail.com\r\n
Traceback (most recent call last):
  File "/usr/lib/pymodules/python2.6/papyon/msnp/base.py", line 107, in _dispatch_command
    handler(command)
  File "/usr/lib/pymodules/python2.6/papyon/msnp/notification.py", line 506, in _handle_MSG
    self._client.oim_box.sync(mail_data)
  File "/usr/lib/pymodules/python2.6/papyon/service/OfflineIM/offline_messages_box.py", line 247, in sync
    self.__parse_metadata(xml_data)
  File "/usr/lib/pymodules/python2.6/papyon/service/OfflineIM/offline_messages_box.py", line 279, in __parse_metadata
    part[0] += part[0].decode(part[1])
TypeError: 'tuple' object does not support item assignment