Picasa deletes EXIF data

http://www.google.as/support/forum/p/Picasa/thread?tid=0d1f649e5114b394&hl=en

Using 3.6.7 for OS X, I found that my photos were missing some EXIF data after adding captions using Picasa. This is very disturbing.

The uploaded photos have data like:

When it should be:

From what I can see, the data missing are: ISO, focus distance and lens model. Should I re-upload all my photos, in case I need the EXIF data later? Is the data still retrievable from the file? Bad Picasa.