Just posted this in
Google Help > Picasa > Discussions > Picasa for Mac (Labs) > PC / Mac Compatibility
(http://www.google.com/support/forum/p/Picasa/thread?tid=0e2e942a3e7212d6&hl=en ):
I'm using a mac with OS X and running vmware fusion with windows XP. Despite what's being said above, I want, recklessly, to try and go back and forth between both windows and mac picasa. Each has some advantages -- i.e. the mac version is faster but the windows one handles geotagging. I find if I go back and forth with the current versions of the program (as of Aug. 2009), things actually kind of work. (This wasn't true with earlier versions.) However, after a bit of edits on the mac, the OS X version of picasa often will create two copies of each picture in a folder, one where my edits are not properly applied. This does not seem to happen to the PC copy. Refreshing the folder doesn't fix things. Moreover, checking the "hidden" picasa files (.picasa.ini file and .picasaoriginals on the mac) reveals that these are not duplicated in any way and don't seem corrupted. What's happening? One workaround that I discovered is that if I carefully do "Folder Menu: Remove from Picasa..." on the whole folder and then "File Menu: Add Folder to Picasa..." things are usually fixed. But I'd like a cleaner solution.
