Help! CS5 keeps messing up my metadata

[raykel6]

I have used PS Elements for years and I have finally upgraded to CS5 and Lightroom 3. I was able to succussfully convert my Elements catalog to Lightroom and all seemed to be going well. However, most of the photos from my last event have the wrong capture date and time in Lightroom and CS5 (it appears to be the date that the photos were uploaded, rather than the date that they were shot). Somehow, a few photos retained the correct metadata, but there is no rhyme or reason to the ones that are correct and the ones that are incorrect. The result is that there is no chronological order to the event photos. The same event was already in my Elements catalog, and all the metadata was correct. Even now, I can view the photos in Elements and all the capture dates and times are correct. I know how to change the metadata manually to the correct date and times in Lightroom, but I am afraid this is going to be an ongoing issue as I get used to the new software. I have tried removing the photos from the catalog and importing them back into my Lightroom library, but the issue persists. Also, I opened up a file that had CORRECT metadata, edited it in CS5 and saved the resulting photo. When I go to the capture date for the new edited photo, it now has INCORRECT metadata (the date of upload, not the shot date).

What could the problem be and how do I fix it and avoid it in the future? Right now its driving me nuts!