In case you haven’t noticed, Picasa is an IPTC train-wreck. If you’re serious at all about annotating your photos, use something else. If they ever catch up, good.
After I started using Photo Mechanic and the address fields for the first time, I would keep finding the contents of the Location field in the State field after letting Picasa update its index. Picasa doesn’t even show address fields so who knows what it’s doing in the background with that. But, finding hundreds of photos saying:
Location: Riverside Cemetery
State: Riverside Cemetery
multiplied by hundreds of other addresses across thousands of photos, and fixing that multiple times (thanks to Photo Mechanic’s Find & Replace option) I had grown very weary.
I didn’t immediately jump to the conclusion that Picasa was causing the problem, but for the past 5 days I haven’t opened Picasa at all and my photos are suddenly fine. The IPTC info is fine in Adobe Elements and ACDSee Pro and XnView. I uninstalled (the now defunct) MediaDex a couple of weeks ago because it was definitely messing around with things. I haven’t uninstalled Picasa yet because I kind of like it for the maps and the face-tagging and its general cuteness and I wish it wasn’t such a pain. I only keep it on my laptop though. I’m still hoping for a New Year’s surprise: Picasa finally gets up to speed with IPTC.
(Update: I think the location problem has been fixed but Picasa still doesn’t accept IPTC annotation for TIFFs which makes it a very bad choice for archivists.)