Yes, I have googled this and found instances going back to 2010 with no satisfactory answer. I have Photoshop 5.1 and the latest ACR and Bridge that work with it. 2011 MAC Mini 10.8.2.
I scanned a landscape oriented printed email image at 800 spi as a portrait orientation and saved it as a tiff. I opened this tiff in Preview and decided it needed more than minor tweaks so I opened it in ACR from Bridge, made a few adjustments and saved it. I thought I could see what I was doing better if it was in landscape orientation again so I opened it in Preview and rotated 90 deg CCW, saved it as a tiff. Going to Bridge I found Open in Camera Raw greyed out. I went back to Preview to see if I could get what I needed in its Tools while viewing it in landscape. Adjustments took forever this time, so I gave up and took a look at the image characteristics. Rotating in Preview had changed the image size to 3.3333...... times larger at 240 ppi still aRGB, still a tiff. This has never happened before, including slow adjustments
I duplicated the rotated file and changed it back to 800 ppi and normal size, went to Bridge, Camera Raw still greyed out. Original unrotated image
that had been edited in ACR and saved will still open in ACR.
All kinds of strange things have happened since updating to 10.8.2, but I don't think this is one of them because of the complaints I have seen that date back to 2010. I did a full maintenance routine, i e cleared RAM, reboot in single user with fsck -fy, repaired permissions, back up with SuperDuper which repairs permissions again. Then I tried Bridge again, original will open, rotated won't.
Anyone know the answe?
The answer is that making edits in ACR and saving it creates layers in the tiff and Bridge will then not open it again in ACR unless you flatten it. I still don't know why Preview increased the image size by 3.333.....x or why ACR increased the tiff file size by 2.6x and why the flattened tiff is 2x the file size of the original scan but the image dimensions are the same. This stuff apparently is above the pay grade of anyone in google, too.