This sounds like a strange occurrence. Can you provide me with a bit more detail on the following:
When this user log in he has a new submission to review, but if he click on the title to begin this task he can't access to the article information.
-- What does he see when he clicks on the title?
Also, after you have assigned the user to the submission, are there checkboxes next to his name that you can see as Journal Manager? Are both boxes checked? You may want to ensure that both boxes are checked and that the "Record" button has been clicked.
Please let me know if you have further questions on this matter.