It seems that some newly-submitted stats had out-of-range stat ID numbers. I'm going to go through the code tomorrow to figure out why this is happening.
I tested it with a single stat for SA2 and that seems to have worked correctly, so maybe it only triggers with large batches.
EDIT: I'll need two or more people who have stats to submit to be in #soniccenter tomorrow (2014/10/13) at around 8 PM 9 PM EDT in order to test the submissions system. (If you submitted stats after I re-enabled submissions earlier today, those stats were deleted due to the rollback. You can help me figure out what's going on by going to #soniccenter tomorrow.)
EDIT 2: [2014/10/13 11:31 AM EDT] I won't be home until around 8:40 PM, so I'll be doing tests at 9 PM tonight.
EDIT 3: [2014/10/13 08:32 PM EDT] Make that 10 PM; extra stuff came up.