I'm thinking about purchasing Photoshop CS4 (student version) but I have 2 computers I use primarily. My Macbook Pro and my Mac Pro. Can I install the software on both computers and use them without any problems? I remember talking to someone on apple store chat and the rep told me that it's possible to INSTALL the program on multiple computers but you can't run them at the same time. So for instance if I'm using CS4 on my Mac Pro, I would have to close out all of my stuff and close the entire program before I could turn around and use it on my Macbook Pro. Is true?