Try this instead:
Open Bridge and select a large bunch of images then Cmd R. (The quantity that you choose will depend on the speed, capacity and DRAM in your computer.)
That will open the whole batch directly into ACR.
Select an image which is typical of others in the loaded batch and apply corrections in ACR.
Then select any other similar ones simultaneously and hit the Synchronize button. Fine tune individually, add star ratings as desired as necessary and hit Done.
When you have collected a number of 5-star Keepers: re-select them as a batch in Bridge and hit Cmd R again.
In ACR, Check that you are in the working space that you require by clicking on the Blue Drop-down menu at the bottom of the page (I use ProPhoto RGB 16-bit);
and also check the option to "Open in Photoshop as Smart Objects".
Select All and click "Open Objects".
[I am now using a newer version than CS4 and you may have to to hold down the Alt or Option key while clicking "Open" in that version.]
All of the selected images will now open as Smart Objects in Photoshop for final finishing and will remain as SOs until the file is either flattened or rasterized.
Clicking on an SO will re-open it in ACR should you wish to make any changes to your previous Edits.
You will need a rasterized layer before you can use the Healing Brush and similar tools however.
I work this way and I find that I can zip through correcting and rating thousands of images in a few days with this method.
I often do a preliminary fly-through making quick corrections and adding capture sharpening and rating the photographs using the 100% view; and then return to the images when I want to actually use them to make final tweaks before opening them in Photoshop.
Hope that this helps ……
Edited by Ann, 29 October 2011 - 18:02 .