To be able to successfully install your custom reports into any openERP database you need the following:

1. You need to have the openERP Report Designer installed into your current database(module name:OpenOffice Report Designer - base_report_designer)

2. Install the plugin provided by the module into LibreOffice/OpenOffice from Tools->Extension Manager, restart the office suit.

3. A new menu should appear 'OpenERP Report Designer', Connect to the current database by clicking on 'Server Parameters'.

4. After that you can create a new report or modify existing one.

You should create three files in order to create a new report, see the following example.

Part 1: Creating the report

.sxw file: this file will help you createing the report layout and to generate the .rml file later on.(e.g new_report.sxw)

.rml file: this file can be generated from .sxw file by clicking on OpenERP Report Designer->Export to RML.(e.g new_report.rml)

.py file: (e.g new_report.py) Example

# -*- coding: utf-8 -*-

import time
from openerp.report import report_sxw

class new_report(report_sxw.rml_parse):
    def __init__(self, cr, uid, name, context):
        super(new_report, self).__init__(cr, uid, name, context=context)
        self.localcontext.update( {'time': time,})

report_sxw.report_sxw('report.new_report', 'account.move',
                      'addons/my_reports/new_report.rml',
                      parser=new_report)

Part 2: Defining the report

You need to create a new python package under addons directory.(e.g my_reports), example:

my_reports.__init__.py : this file must import the python file we previously created.

import new_report

my_reports.__openerp__.py : this file contains informations about our new module.

{
    'name' : 'Zakaria Custom Reports',
    'version' : '1.0',
    'category' : 'Extra Reports',
    'author'  : 'Zakaria',
    'license' : 'AGPL-3',
    'depends' : ['base',],
    'update_xml' : ['my_reports_reports.xml',],
    'installable': True,
    'application': True,
    'auto_install': False,
    'description': '''
This module adds new reports.
============================================================
    '''
}

my_reports.my_reports_reports.xml : this file will define the new report in the database by adding a new record to ir_act_report_xml table.

<?xml version="1.0" encoding="utf-8"?>
<openerp>
    <data>
        <report 
        auto="False" 
        id="new_report_id" 
        model="account.move" 
        name="new_report" 
        rml="my_reports/new_report.rml" 
        string="New Report"/>
    </data>
</openerp>

Now go to settings->Update Module List then go to settings->installed modules and remove the filter 'Installed' then find your module (Zakaria Custom Reports - my_reports) and install it.

Its good idea to take a look at my module as example, it has two reports one for printing the 'Journal Entries' and the other for printing product moves, DOWNLOAD

Hope this will help you..%

UPDATE You need the RML file for the modified report "invoice.invoice", then you need to create a new module that contains the RML file and an XML. but the XML must follow the following form.

<?xml version="1.0" encoding="utf-8"?>
<openerp>
    <data noupdate="0">
        <report
        auto="False"
        id="account.account_invoices"
        model="account.invoice"
        name="account.invoice"
        rml="extra_reports/reports/account_print_invoice.rml"
        string="Invoices"/>
    <data>
<openerp>

Notice the following:

• noupdate="0" : this will search for the report id first, if found then update, else create new record.
• id="account.account_invoices" : the original report id is "account_invoices", but as we are out side the original module we need to add the original module name to the id.

Now go to database, ir_act_window_report_xml and make sure that your report overwrite the original one and not add to the list. Final Note: make sure to set attachment_use column to FALSE.