[opencms-dev] BackOffice problems

[1JOMATO]

Hello pals, I have a big problem developping my own backoffice module. 
I´ve done all what documentation says about this, but this doesn´t 
work. What I done is writing the classes ContentDefinition that extends 
A_CmsContentDefinition and implements I_CmsContent, and the class 
BackOffice that extends A_CmsBackoffice. What I´ve done later is 
writting the templates and pages index, BackOffice and EditBackOffice.
I also make the workplace.properties, but the problems are:

- When I look at the administration view, appears and error icon with 
the name ?????.
-When I click on the icon, instead of the typical view, the template 
appear as it is described here:

  <?xml version="1.0" encoding="ISO-8859-1" ?> 
  <PAGE>
  <CLASS>com.opencms.workplace.CmsWorkplaceDefaultNoCache</CLASS> 
<MASTERTEMPLATE>/system/modules/com.ienet.form/administration/form/index
</MASTERTEMPLATE> 
  </PAGE>

If somebody could help me with this, I´d be very grateful. 

I also wonder if somebody could give me a brief resume on how the 
BackOffice Modules work, what classes I have to redefine and what are 
the steps that opencms follows with the templates(index, backOffice, 
EditBackOffice).