Can not add a new invoice line in supplier invoice if you have saved it before

You can add new supplier invoice lines without problem, but if you save the invoice and then try to add a new line there is an error and you can not add any new line

web-client revno 2772

Log web-client

[16/Dec/2009:11:55:47] HTTP Traceback (most recent call last):
  File "/srv/openerp/launchpad/5.0/client-web/lib/cherrypy/_cprequest.py", line 606, in respond
    cherrypy.response.body = self.handler()
  File "/srv/openerp/launchpad/5.0/client-web/lib/cherrypy/_cpdispatch.py", line 25, in __call__
    return self.callable(*self.args, **self.kwargs)
  File "/srv/openerp/launchpad/5.0/client-web/openerp/controllers/base.py", line 130, in wrapper
    return fn(*args, **kw)
  File "/srv/openerp/launchpad/5.0/client-web/openerp/tools/expose.py", line 204, in func_wrapper
    res = func(*args, **kw)
  File "/srv/openerp/launchpad/5.0/client-web/openerp/controllers/listgrid.py", line 167, in get
    return dict(ids=ids, count=count, view=ustr(wid.render()), info=info)
  File "/srv/openerp/launchpad/5.0/client-web/openerp/widgets/base/base.py", line 196, in render
    return self.display(value, **params)
  File "/srv/openerp/launchpad/5.0/client-web/openerp/widgets/listgrid.py", line 266, in display
    defaults = proxy.default_get(fields, ctx)
  File "/srv/openerp/launchpad/5.0/client-web/openerp/rpc.py", line 390, in <lambda>
    return lambda *args: self._session.execute("object", "execute", self._resource, name, *args)
  File "/srv/openerp/launchpad/5.0/client-web/openerp/rpc.py", line 351, in execute
    return self.gateway.execute(obj, method, *args)
  File "/srv/openerp/launchpad/5.0/client-web/openerp/rpc.py", line 153, in execute
    return self.__execute(obj, method, args)
  File "/srv/openerp/launchpad/5.0/client-web/openerp/rpc.py", line 139, in __execute
    raise common.error(_('Application Error!'), err.backtrace)
  File "/srv/openerp/launchpad/5.0/client-web/openerp/common.py", line 72, in error
    raise TinyError(message=msg, title=title or _("Error"))
TinyError: Traceback (most recent call last):
  File "/srv/openerp/launchpad/5.0/server/bin/netsvc.py", line 244, in dispatch
    result = LocalService(service_name)(method, *params)
  File "/srv/openerp/launchpad/5.0/server/bin/netsvc.py", line 73, in __call__
    return getattr(self, method)(*params)
  File "/srv/openerp/launchpad/5.0/server/bin/service/web_services.py", line 597, in execute
    res = service.execute(db, uid, object, method, *args)
  File "/srv/openerp/launchpad/5.0/server/bin/osv/osv.py", line 61, in wrapper
    return f(self, dbname, *args, **kwargs)
  File "/srv/openerp/launchpad/5.0/server/bin/osv/osv.py", line 120, in execute
    res = pool.execute_cr(cr, uid, obj, method, *args, **kw)
  File "/srv/openerp/launchpad/5.0/server/bin/osv/osv.py", line 112, in execute_cr
    return getattr(object, method)(cr, uid, *args, **kw)
  File "/srv/openerp/launchpad/5.0/server/bin/osv/orm.py", line 2069, in default_get
    value[f] = self._defaults[f](self, cr, uid, context)
  File "/srv/openerp/launchpad/5.0/server/bin/addons/account_tax_include/invoice_tax_incl.py", line 101, in _price_unit_default
    return super(account_invoice_line, self)._price_unit_default(cr, uid, context)
  File "/srv/openerp/launchpad/5.0/server/bin/addons/account/invoice.py", line 982, in _price_unit_default
    if len(taxes[0]) >= 3 and taxes[0][2]:
IndexError: list index out of range

Log server:
[2009-12-16 11:55:47,428] ERROR:web-services:[01]:
[2009-12-16 11:55:47,428] ERROR:web-services:[02]: Environment Information :
[2009-12-16 11:55:47,428] ERROR:web-services:[03]: System : Linux-2.6.28-17-generic-x86_64-with-Ubuntu-9.04-jaunty
[2009-12-16 11:55:47,428] ERROR:web-services:[04]: OS Name : posix
[2009-12-16 11:55:47,428] ERROR:web-services:[05]: Distributor ID: Ubuntu
[2009-12-16 11:55:47,428] ERROR:web-services:[06]: Description: Ubuntu 9.04
[2009-12-16 11:55:47,429] ERROR:web-services:[07]: Release: 9.04
[2009-12-16 11:55:47,429] ERROR:web-services:[08]: Codename: jaunty
[2009-12-16 11:55:47,429] ERROR:web-services:[09]: Operating System Release : 2.6.28-17-generic
[2009-12-16 11:55:47,429] ERROR:web-services:[10]: Operating System Version : #58-Ubuntu SMP Tue Dec 1 21:27:25 UTC 2009
[2009-12-16 11:55:47,429] ERROR:web-services:[11]: Operating System Architecture : 64bit
[2009-12-16 11:55:47,429] ERROR:web-services:[12]: Operating System Locale : es_ES.UTF8
[2009-12-16 11:55:47,429] ERROR:web-services:[13]: Python Version : 2.6.2
[2009-12-16 11:55:47,429] ERROR:web-services:[14]: OpenERP-Server Version : 5.0.7
[2009-12-16 11:55:47,429] ERROR:web-services:[15]: Last revision No. & ID : 1914 <email address hidden>
[2009-12-16 11:55:47,429] ERROR:web-services:[16]:
[2009-12-16 11:55:47,429] ERROR:web-services:[17]: Traceback (most recent call last):
[2009-12-16 11:55:47,430] ERROR:web-services:[18]: File "/srv/openerp/launchpad/5.0/server/bin/osv/osv.py", line 61, in wrapper
[2009-12-16 11:55:47,430] ERROR:web-services:[19]: return f(self, dbname, *args, **kwargs)
[2009-12-16 11:55:47,430] ERROR:web-services:[20]: File "/srv/openerp/launchpad/5.0/server/bin/osv/osv.py", line 120, in execute
[2009-12-16 11:55:47,430] ERROR:web-services:[21]: res = pool.execute_cr(cr, uid, obj, method, *args, **kw)
[2009-12-16 11:55:47,430] ERROR:web-services:[22]: File "/srv/openerp/launchpad/5.0/server/bin/osv/osv.py", line 112, in execute_cr
[2009-12-16 11:55:47,430] ERROR:web-services:[23]: return getattr(object, method)(cr, uid, *args, **kw)
[2009-12-16 11:55:47,430] ERROR:web-services:[24]: File "/srv/openerp/launchpad/5.0/server/bin/osv/orm.py", line 2069, in default_get
[2009-12-16 11:55:47,430] ERROR:web-services:[25]: value[f] = self._defaults[f](self, cr, uid, context)
[2009-12-16 11:55:47,430] ERROR:web-services:[26]: File "/srv/openerp/launchpad/5.0/server/bin/addons/account_tax_include/invoice_tax_incl.py", line 101, in _price_unit_default
[2009-12-16 11:55:47,430] ERROR:web-services:[27]: return super(account_invoice_line, self)._price_unit_default(cr, uid, context)
[2009-12-16 11:55:47,431] ERROR:web-services:[28]: File "/srv/openerp/launchpad/5.0/server/bin/addons/account/invoice.py", line 982, in _price_unit_default
[2009-12-16 11:55:47,431] ERROR:web-services:[29]: if len(taxes[0]) >= 3 and taxes[0][2]:
[2009-12-16 11:55:47,431] ERROR:web-services:[30]: IndexError: list index out of range