**Updated 6 Jan 11: Handle additional missing value**
I believe that we can confirm this issue as well. The additional_attribute_table and entity_attribute_collection columns were empty.
Dolcemilano, your post indicates that there was an issue with character encoding. Try this:
UPDATE `eav_entity_type` SET `attribute_model` = 'customer/attribute', `additional_attribute_table` = 'customer/eav_attribute', `entity_attribute_collection` = 'customer/attribute_collection' WHERE `eav_entity_type`.`entity_type_code` = 'customer';
Obviously, if your Magento tables use a prefix then you would need to adjust accordingly.