I have gotten 12 of these since Weds evening but didn't have any before and nothing has changed in my setup.
They weren't flagged as duplicates just drops..see below from setiq:
s@h/SStats/TotalWuDownload=403
s@h/SStats/TotalResultUpload=263
s@h/SStats/TotalResultDropped=12
s@h/SStats/TotalResultDuplicate=0
More info..it seems to be drop the results from only on system and get the following:
1:52am: s@h_wrk Sending Result: Seti@home status: Program modified
1:52am: Q0001 Seti returned: Program modified
1:52am: s@h_wrk Result dropped 02no02aa.687.28034.629824.139
Will restart the system and see if that helps.