CRM 4 - ArgumentException: An item with the same key has already been added and MessageProcessor fail to process message 'Update' for 'organizationui'

Today I faced a problem with a CRM 4 environment.

I was trying to import the entity Incident from Testing environment to our Quality environment and received an error when trying to import the customization on our Quality environment.

I tryed another thing with our Incident entity of Quality, I tried to change the Incident form and Save the changes and received an error.
After this I turned on the CRM log and tried to obtain more information regarding this problems.The problems I detected with CRM log were:
- ArgumentException: An item with the same key has already been added 
- MessageProcessor fail to process message 'Update' for 'organizationui'.
After this I made a search in Google and found this:

·         http://social.microsoft.com/Forums/en/crm/thread/e061dc2a-f039-43fa-b7bf-384b3f222aee

Witch made me find another link:

·         http://support.microsoft.com/kb/947096

With this two links and CRM log I managed o find a third link:

·         http://altaixrm.blogspot.pt/2010/12/find-that-pesky-workflow-that-is.html

With this last link I managed to achieve the following query:

select * from OrganizationUIBase as organizationui0
where (organizationui0.FormId = 'dc89c020-8bda-48c4-8b89-f2aaf9e48670')

The result of this query was:

After analise the 3 rows I found out that the first row had the FormXml field with a invalid XML and this was the cause of my problem.

The solution was to delete this line.

After a backup of course.

Just as a note, this was the second problem I faced, the first one was resolved by the first link above and I'm not talking about it because there is lot of information on the link and on the net about it.