iPhoto and Metadata
For a long time I've been keywording my photos using various tools on Windows that all seemed to agree with each other on how to get keywords into and out of photos. Picasa, Lightroom, and Bridge were all able to see the keywords that were written into the files.
I just imported all these photos into my wife's MacBook, and now some, but not all, of the keywords have gone missing. Not only that, but for a lot of photos (but not all of them), it's used the "last modified" date of the file as the date the picture was taken, not the data that's in the metadata.
I know the right data is in the files; I can see it if I use exiftool to look at them. But using mdls (the Spotlight command line query tool) shows the keywords didn't make it into Spotlight's database when I moved them to the Mac.
One file in particular whose keywords have gone missing has the keyword stored in an XMP packet. Other files use other places that keywords can be stored (like EXIF) so maybe this is the reason some work and some don't.
Losing the keywords and the date the photo was taken makes these pictures pretty much disappear from history. I'm very disappointed that iPhoto didn't get basic feature this right. It's unbelievable that we're as far into the digital photography revolution as we are, and yet there still aren't widely accepted and reliable standards for metadata that all software can agree on.