Since I have upgraded to CS6 I've noticed that when transforming an object it does not maintain the aspect ratio even when I am holding shift while transforming. I have to each time check the link button (maintain aspect ratio)
It's seems to work here on photoshop cs6 13.01.1 on windows 7 x64.
Does it happen on anything you try to transform or just certain documents or layer types?
What operating system are you using?
Have you installed all the latest updates by going to Help>Updates from within photoshop cs6?
So it always works when you press the Maintain Aspect Ratio button, but never works when holding down the shift key?
I'm sure you know this, but the maintain aspect ratio only works when using one of the corner handles and not one of the side handles.
Have you tried resetting the photoshop cs6 prefrences and also verifying that the shift key is actually working?
Reset the photoshop preferences by holding down the Shift+Option+Cmd keys while starting photoshop and keep holding
down the keys until you get a dialog asking if you want to delete the photoshop settings file. Then press Yes.
Yes, if we click on the "Maintain aspect ratio" button it will transform correctly but not when holding the shift key.
I am an experienced Photoshop user, so yes I am aware that the aspect ratio only works when you use the corner handle. Yes, my shift key works. We just had our work computers upgraded to CS6 so I haven't changed the Photoshop preferences other than changing the rulers to pixels. As I stated earlier, my coworker also has the same problems so this is not an individual user error. At work Tech looked at the problem and didn't know how to fix and suggested I try asking in the Adobe forum.
It'll be because 'Snap Vector Tools and Transforms to Pixel Grid' is enabled in 'Preferences > General', an option that didn't exist before CS6. It's actually being more truthful that way because the transformed layer has to become an integer number of pixels wide and tall, anyway, and that's not going to be a perfectly proportional scale in most cases.
See what I mean by trying to scale an 11 x 10 pixels layer by 50%. It's impossible for that to be scaled by exactly 50% in width because the result has to be either 5 or 6 pixels wide (it will be 6). When the 'Snap...' preference is disabled (i.e. the pre-CS6 behaviour) you can scale the bounding box by precisely 50% in width but the pixels don't cover precisely 50% of the original width. When the preference is enabled, you won't be misled by being able to scale the bounding box to precisely 50% when the pixels cannot cover precisely 50%.