Two problems have been discovered after upgrading Apple computers to Yosemite (OS X 10.10). They are graphical issues and can be worked around with some inconvenience. However, unless you need to for other reasons, I would recommend holding off on upgrading to Yosemite until I can find a work around in AIJ code, or Apple releases a fix to correct the problem either in the OS or the associated java version.
The main problem is that if any white shows around the sides of your image in the image display, the display of apertures will be shifted from the associated star. As long as you zoom in far enough to remove all white from the edges of the image, the apertures will re-align with the star. The out-of-alignment issue is a display problem only and will not affect the actual region of the image that is analyzed while running photometry. So, if you zoom in to place apertures and ensure they are placed properly around the star and then zoom back out too far while photometry is running, the photometry will still be good.
The second problem is that the y-axis plate scale characters are reversed. The y-axis plate scale can be turned off in the 'View' options above the image without much loss of info, since most cameras (I think) have square pixels anyway. The x-axis plate scale display is controlled separately and can remain enabled.
I'll try to find solutions as soon as possible.