Just purchased a Mac Mini and installed from disc my CS4. It is not opening any raw files taken with the Canon 50D, but will open raw files taken with Canon 20D. This photoshop CS4 was working fine for ALL of these files when it was installed in my old Mac Pro tower (vintage 2006). Why is it working for one group of files and not the other? What could have gone wrong in the reinstall process??
Also, you should install the rest of the photoshop cs4 updates such as 11.02 by going to Help>Updates from within photoshop or bridge cs4.
The installed version of photoshop cs4 from disc doesn't have any of the updates such as camera raw 5.7