I had trouble finding any info about LR3 compatibility, infact, I didn't therefore I cannot answer the question.
Only a suggestion though, upgrade it to the 5.x release for just few USD, it's worth it and you'll be not afraid to install OSX 10.10 on your MAC ...
Thank you so for your reply. I may just update. However, since Yosemeite
just came out, I might wait a few more weeks/months to see if any other
replies come through. At least I do have an alternative route. Have a
I was running LR 3.6 on my MacBook Pro when I upgraded to OS X Yosemite and it worked fine. A few weeks ago I decided to upgrade to LR 5.6 (mostly for the advanced healing brush features).
Here is a link describing the features of the various LR versions... Compare Lightroom versions, version history | Adobe Photoshop Lightroom 5