Carlos,
This is very well know issue with SP6 upgrade. One of the pre-requesite for SP6 is that the Administrator password MUST be complex. See link below to other SCN Blogs that can help you resolve your issues.
Not able to find and Unable to create an SIA in BO 4.1 SP06 Installation
SIA is not created during install
Follow the steps in the SAP Note below to help you resolve the issues
http://service.sap.com/sap/support/notes/2184827
Regards,
Ajay