RBowers@nyiso.com writes to the NYISO_TECH_EXCHANGE Discussion List:

This notice is to inform Transmission Customers that the September 20, 2001
OATT Schedule 1 residual adjustments are artificially inflated in the first
version of the advisory billing statements.  A file used in the computation
of subzonal loads was not loaded prior to the billing run making it appear
as though no load existed in some subzones.  This  causes all DAM scheduled
purchases and bilateral transactions serving load in the affected subzones
to be sold back in the Balancing Market.  This creates an under-collection
which is then recovered from the market through the balancing energy,
losses, & congestion residuals .  The 20th will be rerun as soon as price
corrections and metered MWh values have been reconciled.  The NYISO
apologizes for any inconvenience caused by this problem.

Regards,
Randy A. Bowers
Manager - Customer Settlements