McMoRan Exploration (MMR -15%) shares plunge for a second day after reporting new difficulties at its Davy Jones field that add to doubts about its commercial viability. Capital One says MMR faces greater risk in light of yesterday's news, adding to negative comments from J.P. Morgan and RBC Capital. Other energy explorers with stakes in Davy Jones are impacted: PXP -0.8%, EXXI -1.7%.