Preference for Processing RAW in LR or PS Camera Raw

Question

I'm not finding this setting anywhere, and it seems to arbitrarily go back and forth, after updating software or installing software. Hoping someone can help.
When using an external editor (PS CS5) to edit photos from Lightroom 3, there is an inital preference to select whether to use ACR in PS to process the raw file, or to use LR.  I always want to do this in PS.  There's often times where I'm compositing multiple photos.  I only need to open up that raw file to quickly grab a section of it to move into another file.  I don't want to save the raw file as a psd, tif or whatever, just select, copy and move that section of the file and then close it.
The problem is that preference setting is only when you first set up the Lightroom, I'm not seeing it anywhere on any of the preference menus.  And for some reason, it has switched to processing the raw in Lightroom.  So now i'm ending up with useless psd files.  That takes up space on my hard drive, takes longer to archive on to external hard drives, and is slower to open the files into PS.  It may seem like a small inconvenience, but when shooting 1000s, or 10000s of images a week it adds up quickly.  And to get rid of them, i have to reveal in finder, then delete, then remove from catalog in LR - which just wastes time.
Am i missing something? If anyone knows how to set this or a workaround i'd love to hear it.
Sys specs, if it matters
Mac Pro, dual quad-core, 16gb ram, GeFOrce 8800 GT 512mb graphics card
OS X Snow Leopard
LR 3.6
5d Mk II CR2 files
PS CS5 (12.0.4) and also the newest prerelease (can't disclose much on this)
LR and PS are both great in their own right, and do things better than the other in some situations, I wish Adobe would make them play nicer together.

Answer 1

7. Feb 16, 2012 6:05 PM (in response to b_gossweiler) 
Re: Preference for Processing RAW in LR or PS Camera Raw
In any event even if you choose to edit the original in PS, as I believe you should be able to do you will still end up with a Tiff, PSD or jpeg file when you have finished your work in PS. Then why are you using Lightroom? This will have a bearing on the advice you will get.
Like I said above, LR and PS both serve specific functions, and yes they do overlap in some areas, and I yes do use both in my workflow.  PS isn't a cataloging program.  LR doens't have layers and sucks at complex editing tasks.  There's 2 reasons i use both, amoung many many others. 
The point of my question is that i don't want LR creating and saving PSD files on my hard drive when i don't need a PSD of that specific photo.  You use to be able to make LR open a raw file in PS and use ACR to processs it.  That meant you could close the raw file in Photoshop, and nowhere along the way was a PSD file, or any other file saved.