From this notice, it sounds as if CME is adjusting marings down to prevent margin calls for those forced to move their positions due to MF's bankruptcy. Makes more sense. From a post by the cork on ihub:

SUBJECT: CME Group Clarifies Maintenance Margin Ratios; Exchange to Reduce Initial
Margin Ratio to 1.00

FOR THE FULL TEXT OF THIS ADVISORY :
http://www.cmegroup.com/tools-information/lookups/advisories/clearing/files/Chadv11-400.pdf


CME Group Clarifies Maintenance Margin Ratios; Exchange to Reduce Initial Margin

Ratio to 1.00

CME Group today is clarifying its notice to clearing firms regarding margins. In light of the issues customers transferring out of MF Global are facing, while still maintaining appropriate risk management protections for the market, CME Clearing is setting the "initial" margin upcharge at zero. This upcharge is normally applied to customer accounts when they are receiving a margin call.

The intent and effect of these changes is to decrease the size of any margin calls resulting from
the bulk transfer of MF Global customers to new clearing members, not to increase them.

Yesterday, CME Group successfully transferred MF Global customer positions to a new clearing member with part, but not all, of their funds, as approved by the bankruptcy trustee and the court. By reducing the initial margin “ratio” to 1.00, we ensure that margin calls that are issued to these transferred MF Global customers will be limited to bringing their accounts into compliance with the lower, “maintenance” margin levels. Maintenance margins are set to provide appropriate risk management coverage. Initial margins are set to provide an additional buffer against future losses in the account.

This is a short term accommodation to maintain market integrity and provide temporary relief to customers whose accounts have been disrupted by this event.

We apologize for any confusion our initial advisory may have created.