If anyone's still experiencing this problem, I may have stumbled upon a solution. I had this same problem, too. Rebuilding the icon cache would help for a few days, but after a while, icons would go back to randomly shrinking. I'm running Windows 7 64 bit.


A couple of months ago, I decided that when I launched a game, I wanted the volume to automatically be at a certain level. To achieve this, I used a free program called Autohotkey. I made a script for each new game I get using the info below, and not only does the volume change automatically when the game is launched, but the shrinking problem has gone away, too. Right now, the only icon in my folder that changes size on its own is the only one I haven't made a shortcut for yet. It's still the original Steam shortcut.


#NoTrayIcon
#SingleInstance force
soundset 28
run "steam://rungameid/600370"
return