I'm confused and a bit aggravated about ACR versions.
I couldn't seem to find ACR as a program in finder>applications so went searching to see what version of ACR I had via opening PSE8 and found that it was 18.104.22.168. However, when I try to go from LR4 to edit in photoshop it tells me that the version I have installed is 4.0....
I installed CS3 after I'd already had PSE8 (which came with the CS4 ACR so I assume that's where the 6.2 came from).
Why doesn't LR4 (which I understand wants 7.0 - tho I can't seem to be allowed to download that without CS6 or even ACR 6.6 which I can't seem to be allowed to download without CS5 - and that's not the reall issue - I don't think) even recognize that ACR 6.2 exists?? All was fine with LR3.
LR3.x is compatible with ACR 6.x that comes with PS-CS5 and whatever versions of Elements that were released when some version of ACR 6.x was the current version.
LR4.x is compatible with ACR 7.x that will come with PS-CS6 and should be compatible with PSE10 with at least an ACR 6.7 update which is not quite available, yet, but more compatible with an ACR 7.1 update that I would expect will come out not too long after PS-CS6 ships.
I think that’s why LR3 was happy with ACR 6.2 while LR4 is not.
If you installed Photoshop CS 3, the last version of ACR that is compatible with that version of Photoshop is version 4.6. If you are going to use that version of Photoshop then it will be necessary for you to render a copy with Lightroom adjustments and send that to Photoshop. CS 3 is now in nearly three versions old, and is no longer supported and no updates for anything related to CS 3 will ever be available.