If I try to open ID error 4 occurs. PS and ILL are working fine. I have this problem on 2 of my new, well working Apple computers. I already deinstalled CS 5 let the Adobe cleaning tool run and installed CS 5 again. But ID is not opening. All other programs are working fine.
What is the exact error message?
Try deleting the two InDesign folders in your user Library/Profile. See Replace Your Preferences for the locations of these folders in your OS. Note that these will be HIDDEN folders and you will need to show hidden files and folders to find them.