As far as i can tell it's working in photoshop cs6 13.01.1 on a windows 8 x 64 system for both tif and psd files.
What operating system and version of photoshop cs6 are you using?
Have you applied the latest updates from within photoshop cs6: Help>Updates?
Many thanks for the reply. I should have specified the operating system and the version of Photoshop.
I am on Mac OSX 10.8.2 with Photoshop 13.0.4 x 64.
Could someone try on a Mac to see if they have this problem?