December 28, 2007 Filing in Compliance with the Commission's 12/20/07 "Order Instituting a Section 206 Investigation and Denying Motion for Reconsideration and Clarification" of the California ISO in Docket Nos. ER06-615-017, ER07-1257-001, ER02-1656-035, EL08-20-000 and EL05-146-006 (MRTU/RCST)