John,
Thank you for the reply. Actually, my issue was only one image discussed in the other thread I linked to above. I solved that by simply removing the image, going back to my original and re-importing that. In this thread I was trying to give Dan, the original poster, some more info. Unfortunately I don't think I've helped him much! Dan appeared to have a more serious problem.
My issue was specific to one image among many on a similar drive/folder. The "?" was there but LR could find it and the folder was connected. It was strange... [mac OS 10 BTW]
But regardless, you make a statement below that is a bit above me:
If you are running a centralized database of the image adjustments, then yes, you can make adjustments even when the images are not present. If you use an .xmp workflow then you cannot make adjustments unless the images are linked to LR correctly.
The image I has problems with was a jpeg converted to dng. My typical workflow involves LR catalog on my mac (macbook pro - that's all I got right now), with images stored on external LaCie drives. Those are backed up to a few network drives. The images are almost all DNG's, with a few psd's or jpegs mixed in. I'm not sure if this is a "centralized database of image adjustments" or not. I'm guessing not, since I thought the dng's use xmp files, but they are 'bucketed' together in the overall dng package. I have LR set up
not to auto write to the xmp, but I save them all out (cmd-S) before I exit.
Dave