RBowers@nyiso.com writes to the NYISO_TECH_EXCHANGE Discussion List:  The settlements curently posted for September 28-Version 2 & 29-Version 1, 2001 are not accurate due to problems encountered with some data files for those dates.
As a result, some customer balancing energy is incorrect and residual adjustments for those dates are artificially inflated.
The NYISO will be re-running those billing dates as soon as it is feasible to do so.
The NYISO apologizes for any inconvenience caused by this problem.
Regards,

September 28-V2 & 29-V1, 2001 settlement postings