It must have been over a year now since Adobe decided to change the scaling shortcut in Photoshop, so you now don't hold shift to retain proportions.
I use Illustrator and Photoshop every day and I still haven't managed to get used to the new scaling shortcuts. It drives me nuts! When you're working in both AI and PS it's too difficult to remember not to hold shift or to hold shift.
I waste too much time everyday having to undo something after I've scaled it because I accidentally held or didn't hold the shift key. Will Adobe ever consider changing this back to the way it was before?