what will be reason for the error?

If i apply schedule upgrade on installed module I get following error message. The client view do not allow me for logout so I need to stop server

No LSB modules are available.
[2010-05-11 19:35:40,475] ERROR:init:[01]:
[2010-05-11 19:35:40,475] ERROR:init:[02]: Environment Information :
[2010-05-11 19:35:40,475] ERROR:init:[03]: System : Linux-2.6.24-26-generic-x86_64-with-debian-lenny-sid
[2010-05-11 19:35:40,476] ERROR:init:[04]: OS Name : posix
[2010-05-11 19:35:40,476] ERROR:init:[05]: Distributor ID: Ubuntu
[2010-05-11 19:35:40,476] ERROR:init:[06]: Description: Ubuntu 8.04.3 LTS
[2010-05-11 19:35:40,476] ERROR:init:[07]: Release: 8.04
[2010-05-11 19:35:40,476] ERROR:init:[08]: Codename: hardy
[2010-05-11 19:35:40,476] ERROR:init:[09]: Operating System Release : 2.6.24-26-generic
[2010-05-11 19:35:40,477] ERROR:init:[10]: Operating System Version : #1 SMP Tue Dec 1 17:55:03 UTC 2009
[2010-05-11 19:35:40,477] ERROR:init:[11]: Operating System Architecture : 64bit
[2010-05-11 19:35:40,477] ERROR:init:[12]: Operating System Locale : en_IN.ISO8859-1
[2010-05-11 19:35:40,477] ERROR:init:[13]: Python Version : 2.5.2
[2010-05-11 19:35:40,477] ERROR:init:[14]: OpenERP-Server Version : 5.0.6
[2010-05-11 19:35:40,477] ERROR:init:[15]: Last revision No. & ID :
[2010-05-11 19:35:40,478] ERROR:init:[16]: <record id="view_bug_tree" model="ir.ui.view">
[2010-05-11 19:35:40,478] ERROR:init:[17]: <field name="name">bug.tracker</field>
[2010-05-11 19:35:40,478] ERROR:init:[18]: <field name="model">bug.tracker</field>
[2010-05-11 19:35:40,478] ERROR:init:[19]: <field name="type">tree</field>
[2010-05-11 19:35:40,478] ERROR:init:[20]: <field name="view_mode">tree</field>
[2010-05-11 19:35:40,479] ERROR:init:[21]: <field name="arch" type="xml">
[2010-05-11 19:35:40,479] ERROR:init:[22]: <tree>
[2010-05-11 19:35:40,479] ERROR:init:[23]: <field name="bug_id"/>
[2010-05-11 19:35:40,479] ERROR:init:[24]: <field name="name"/>
[2010-05-11 19:35:40,479] ERROR:init:[25]: <field name="type"/>
[2010-05-11 19:35:40,479] ERROR:init:[26]: </tree>
[2010-05-11 19:35:40,480] ERROR:init:[27]: </field>
[2010-05-11 19:35:40,480] ERROR:init:[28]: </record>
bzr: ERROR: Not a branch: "/usr/lib/python2.5/site-packages/openerp-server/".
No LSB modules are available.
[2010-05-11 19:35:40,881] ERROR:web-services:[01]:
[2010-05-11 19:35:40,881] ERROR:web-services:[02]: Environment Information :
[2010-05-11 19:35:40,881] ERROR:web-services:[03]: System : Linux-2.6.24-26-generic-x86_64-with-debian-lenny-sid
[2010-05-11 19:35:40,881] ERROR:web-services:[04]: OS Name : posix
[2010-05-11 19:35:40,882] ERROR:web-services:[05]: Distributor ID: Ubuntu
[2010-05-11 19:35:40,882] ERROR:web-services:[06]: Description: Ubuntu 8.04.3 LTS
[2010-05-11 19:35:40,882] ERROR:web-services:[07]: Release: 8.04
[2010-05-11 19:35:40,882] ERROR:web-services:[08]: Codename: hardy
[2010-05-11 19:35:40,883] ERROR:web-services:[09]: Operating System Release : 2.6.24-26-generic
[2010-05-11 19:35:40,883] ERROR:web-services:[10]: Operating System Version : #1 SMP Tue Dec 1 17:55:03 UTC 2009
[2010-05-11 19:35:40,883] ERROR:web-services:[11]: Operating System Architecture : 64bit
[2010-05-11 19:35:40,883] ERROR:web-services:[12]: Operating System Locale : en_IN.ISO8859-1
[2010-05-11 19:35:40,883] ERROR:web-services:[13]: Python Version : 2.5.2
[2010-05-11 19:35:40,884] ERROR:web-services:[14]: OpenERP-Server Version : 5.0.6
[2010-05-11 19:35:40,884] ERROR:web-services:[15]: Last revision No. & ID :
[2010-05-11 19:35:40,884] ERROR:web-services:[16]: Exception in call: Traceback (most recent call last):
[2010-05-11 19:35:40,884] ERROR:web-services:[17]: File "/usr/lib/python2.5/site-packages/openerp-server/wizard/__init__.py", line 74, in execute_cr
[2010-05-11 19:35:40,884] ERROR:web-services:[18]: action_res = action(self, cr, uid, data, context)
[2010-05-11 19:35:40,885] ERROR:web-services:[19]: File "/usr/lib/python2.5/site-packages/openerp-server/addons/base/module/wizard/wizard_module_upgrade.py", line 92, in _upgrade_module
[2010-05-11 19:35:40,885] ERROR:web-services:[20]: db, pool = pooler.restart_pool(cr.dbname, update_module=True)
[2010-05-11 19:35:40,885] ERROR:web-services:[21]: File "/usr/lib/python2.5/site-packages/openerp-server/pooler.py", line 62, in restart_pool
[2010-05-11 19:35:40,885] ERROR:web-services:[22]: return get_db_and_pool(db_name, force_demo, status, update_module=update_module)
[2010-05-11 19:35:40,886] ERROR:web-services:[23]: File "/usr/lib/python2.5/site-packages/openerp-server/pooler.py", line 40, in get_db_and_pool
[2010-05-11 19:35:40,886] ERROR:web-services:[24]: addons.load_modules(db, force_demo, status, update_module)
[2010-05-11 19:35:40,886] ERROR:web-services:[25]: File "/usr/lib/python2.5/site-packages/openerp-server/addons/__init__.py", line 728, in load_modules
[2010-05-11 19:35:40,886] ERROR:web-services:[26]: r = load_module_graph(cr, graph, status, report=report)
[2010-05-11 19:35:40,886] ERROR:web-services:[27]: File "/usr/lib/python2.5/site-packages/openerp-server/addons/__init__.py", line 618, in load_module_graph
[2010-05-11 19:35:40,887] ERROR:web-services:[28]: tools.convert_xml_import(cr, m, fp, idref, mode=mode, **kwargs)
[2010-05-11 19:35:40,887] ERROR:web-services:[29]: File "/usr/lib/python2.5/site-packages/openerp-server/tools/convert.py", line 885, in convert_xml_import
[2010-05-11 19:35:40,887] ERROR:web-services:[30]: obj.parse(xmlstr)
[2010-05-11 19:35:40,887] ERROR:web-services:[31]: File "/usr/lib/python2.5/site-packages/openerp-server/tools/convert.py", line 779, in parse
[2010-05-11 19:35:40,888] ERROR:web-services:[32]: self._tags[rec.nodeName](self.cr, rec, n)
[2010-05-11 19:35:40,888] ERROR:web-services:[33]: File "/usr/lib/python2.5/site-packages/openerp-server/tools/convert.py", line 747, in _tag_record
[2010-05-11 19:35:40,888] ERROR:web-services:[34]: id = self.pool.get('ir.model.data')._update(cr, self.uid, rec_model, self.module, res, rec_id or False, not self.isnoupdate(data_node), noupdate=self.isnoupdate(data_node), mode=self.mode )
[2010-05-11 19:35:40,888] ERROR:web-services:[35]: File "/usr/lib/python2.5/site-packages/openerp-server/addons/base/ir/ir_model.py", line 474, in _update
[2010-05-11 19:35:40,888] ERROR:web-services:[36]: model_obj.write(cr, uid, [res_id], values)
[2010-05-11 19:35:40,889] ERROR:web-services:[37]: File "/usr/lib/python2.5/site-packages/openerp-server/addons/base/ir/ir_ui_view.py", line 131, in write
[2010-05-11 19:35:40,889] ERROR:web-services:[38]: return super(view, self).write(cr, uid, ids, vals, context)
[2010-05-11 19:35:40,889] ERROR:web-services:[39]: File "/usr/lib/python2.5/site-packages/openerp-server/osv/orm.py", line 2353, in write
[2010-05-11 19:35:40,889] ERROR:web-services:[40]: fobj = self._inherit_fields[field][2]
[2010-05-11 19:35:40,889] ERROR:web-services:[41]: KeyError: 'view_mode'
> /usr/lib/python2.5/site-packages/openerp-server/osv/orm.py(2353)write()
-> fobj = self._inherit_fields[field][2]

I don't get reason.
Shankar