Nothing puzzling really. If you've followed progress of imm. "reform" the past 2 years you'd know of the heat the Onbudsman's office brought on the DHS to use up visa numbers for the year. So now the DHS waits until about June/July to see how many numbers the USCIS is chewing up (case in point Jul 2007, Aug 2008) and then moves the dates ahead the last 2 months before the "new" year so as to max out visa number usage. Thats what happened in Aug. Now apparently owing to the lethargy exhibited by the USCIS (NSC in particular) half the month is gone and they've not requested as many numbers as expected. DHS has progressed the dates further assuming less demand. So now folks with PDs in Aug 2006 can get GCs if their RDs are early while those from 2003/4/5 may be left holding the bag... Go figure!!