SQL server permissions ?

I found a script that let me look at permissons on the server. There are two sets of permissions on the database for the user account.  One set gives all the object_or_coumn and the other set for the same User ID give a NULL in that column.  Could this be causing a conflict as to permissons for this user ID or is the Null Value suppose to be here.  This ID cannot logon to the database.  Get error.

xxx\IUSR_xx      WINDOWS_USER  OBJECT_OR_COLUMN  QSASafetyInfo              ALTER      GRANT
xxx\IUSR_xx      WINDOWS_USER OBJECT_OR_COLUMN   QSASafetyInfo      CONTROL      GRANT
xxx\IUSR_xxxWINDOWS_USER OBJECT_OR_COLUMN QSASafetyInfo      DELETE      GRANT
xxx\IUSR_xxxWINDOWS_USER OBJECT_OR_COLUMN QSASafetyInfo      INSERT      GRANT
xxx\IUSR_xxx WINDOWS_USER OBJECT_OR_COLUMN QSASafetyInfo      SELECT      GRANT
Here is the second set that shows up.

xxx\IUSR_xxxWINDOWS_USER      DATABASE      NULL      AUTHENTICATE      GRANT
xxx\IUSR_xxxWINDOWS_USER      DATABASE      NULL      CONTROL      GRANT
xxx\IUSR_xxxWINDOWS_USER      DATABASE      NULL      CONNECT      GRANT
xxx\IUSR_xxxWINDOWS_USER      DATABASE      NULL      DELETE      GRANT
xxx\IUSR_xxxWINDOWS_USER      DATABASE      NULL      EXECUTE      GRANT
xxx\IUSR_xxxWINDOWS_USER      DATABASE      NULL      INSERT      GRANT
xxx\IUSR_xxxWINDOWS_USER      DATABASE      NULL      SELECT      GRANT
xxx\IUSR_xxxWINDOWS_USER      DATABASE      NULL      UPDATE      GRANT
xxx\IUSR_xxxWINDOWS_USER      OBJECT_OR_COLUMN      QSASafetyInfo UPDATE      GRANT