OpenERP version 6, My Timesheet form crashed after inherited - odoo

Question

In OpenERP version 6, in my custom module, I changed the Timesheet form view by inheriting as my custom view below:
<record id="oit_hr_timesheet_sheet_form" model="ir.ui.view">
<field name="name">oit.hr.timesheet.sheet.form</field>
<field name="model">hr_timesheet_sheet.sheet</field>
<field name="inherit_id" ref="hr_timesheet_sheet.hr_timesheet_sheet_form" />
<field name="type">form</field>
<field name="arch" type="xml">
<data>
<button name="sign_in" position="replace"/>
<button name="sign_out" position="replace"/>
<field name="state_attendance" position="after">
<field name="day_attendance"/>
</field>
<field name="total_attendance_day" position="replace"/>
<field name="total_difference_day" position="replace"/>
<field name="total_timesheet_day" position="replace"/>
<field name="timesheet_ids" position="after">
<field name="day_difference"/>
<field name="day_timesheet"/>
</field>
<page string="By Day" position="replace" />
<notebook position="inside">
<page string="Time balance">
<group colspan="4" col="2" width="600">
<field name="time_account_balance"/>
<field name="working_hour"/>
<field name="attendance_hour"/>
<separator string="Timesheet numbers until the viewed working period." colspan="4" />
<field name="total_time_account_balance"/>
<field name="total_working_hour"/>
<field name="total_attendance_hour"/>
</group>
</page>
</notebook>
</data>
</field>
</record>
Then the Human Resources / Time Tracking / My Timesheet form totaly crash. But when I go to Administration / Customization / User Interface / Menu Items, and I choose "My Timesheet" menu item to fix its action from "ir.actions.server" to "ir.actions.act_window" and select object "hr_timesheet_sheet.sheet", then choose my view "oit.hr.timesheet.sheet.form" for object's form view, choose my view "oit.hr.timesheet.sheet.tree.simplified" for object's tree view.
Then I have "My Timesheet" form shown correctly.
Why is that? I think there is somethings in my view code not work with "My Timesheet" menu and "ir.actions.server" defined in file hr_timesheet_sheet/hr_timesheet_sheet_data.xml, Here I paste the openerp6 code in hr_timesheet_sheet_data.xml:
<record id="ir_actions_server_timsheet_sheet" model="ir.actions.server">
<field eval="5" name="sequence"/>
<field eval=""""code"""" name="state"/>
<field eval=""""ir.actions.server"""" name="type"/>
<field name="model_id" ref="model_hr_timesheet_current_open"/>
<field eval="[(6,0,[])]" name="child_ids"/>
<field eval=""""action = self.pool.get('hr.timesheet.current.open').open_timesheet(cr, uid, object.id, context)"""" name="code"/>
<field eval=""""True"""" name="condition"/>
<field eval=""""My Timesheet"""" name="name"/>
</record>
<record id="menu_act_hr_timesheet_sheet_form_my_current" model="ir.ui.menu">
<field name="name">My Timesheet</field>
<field eval="1" name="sequence"/>
<field name="parent_id" ref="hr_attendance.menu_hr_time_tracking"/>
<field name="icon">STOCK_JUSTIFY_FILL</field>
<field name="action" ref="ir_actions_server_timsheet_sheet"/>
</record>
Kindly please help me to have correct view code or a solution so that I will not need to change information for menu "My Timesheet" after I upgrade my custom module! thanks a lot!