Thank you for your response.
The camera in questions is a Canon 7D (actullay I shoot with a pair of 7D's and the results are the same for both cameras), the files are both .CR2 and .JPG, with the same results being seen for both file formats. the images have not been edited in any other applications but viewed immediately after donwload to the PC from the memory card.
I have also viewed these and other older images in both the CS6 and CS5 versions of bridge for comparision purposes and see the same differences irrespective of how old the image is or if its been previously edited in CS5 for both .CR2 and .JPG files.
In addition I also don't see an indication of the subject distance displayed in CS6 bridge, although the option is selected and works as expected in CS5 bridge.
I will send you a seperate email with screen shots showing an example in both CS5 and CS6.
We found that Lens Specification is new to Exif 2.3 specification, so most Cameras might not support that well, I checked that it seems even 5D MarkIII does not write the complete LensSpecification info into its .CR2 files, so that's the reason why "F0" shows for LensSpecification in Bridge Metadata Panel. This is not a bug.
For subject distance, we are still investigating the issue.
Thank you for keeping me informed of the progress of the investigations. The Lens specification behaviour now makes sense, may be worth including an explanation in the release notes or FAQ though.
Appreciate your engineers continuing to investigate the Subject distance information issue.