VPHOT error positioning aperture

American Association of Variable Star Observers (AAVSO)
Sat, 04/13/2013 - 16:18

I submitted two images of RR Tau (V and I) to VPHOT this morning and got some strange readings.  Upon looking closely at the images, the aperture was askew.  Placing the cursor on the aperture indicated its position was NOT that of RR Tau (the star image WAS at the correct position).  The comp stars and check star were aligned properly.  Images taken recently before last night are okay.  What could be going on?

Jim Roe [ROE]