I get a very similar problem, but it's not always the first file I try to open. I can be opening tons of images, edit, save, close them and sometimes when I try to open another file it will just sit there for a minute. Whenever it happens, I get the watch cursor, with its minute/hour hand ticking away; and not the spinning color cursor that OS X uses when a program refuses to respond. So Photoshop is definitely doing something but I'm not sure what. Maybe it's trying to read a corrupted embedded color profile, maybe some metadata?