There are RAW-specific and non-RAW-specific profiles. The problem could be that ACR is using a RAW-specific profile which exists, but after you open an image in PS, it is no longer RAW so PS would always be looking for a non-RAW profile, which there may not be one of—most profiles are only for RAW. Since there could be a problem using a RAW profile with non-RAW image--the profile might correct things that have already been corrected, PS requires you to make a manual selection, to judge whether the profile is being used appropriately or not.
The question becomes, if you have the correct profile in ACR, why would you need to apply the lens-profile, again, once the image is in PS, or were you just curious why ACR and PS were acting differently?
I was just curious and hunting around ACR 7.1 and Photoshop trying our the features. Also I have found that LR4 RC2 has follows ACR 7.1 as far as lens profiles go working with RAW images, so there is some consistency.
Wonder what the difference is between a RAW rendered image in ACR versus a Photoshop rendered image. Given, I could be wrong here, that Lens Correction is based on the optics of the lens, focal length, and the characteristics of the sensor, so would they not be the same in ACR and Photoshop?
I think I need to go check out a lens profiler
There is one reason that I may go back into the Lens Correction Filter and that might be to fine tune some of the persective tools. With a large panorama much easier to see what needs to be done rather than view seperate images, and i have done that in the past. did not come to me until after I had hit the Send Button