A few months ago, we upgraded (finally) from CS3 to CS6. (I'm running Mac OS 10.6.8.)
Unfortunately, when I go FILE -> OPEN then type part of a file name in the SEARCH bar, no InDesign files show up---CS3 or CS6 files. I have to manually switch the dialog box from "All Readable Documents" to "All Documents" then I get all files, including InDesign files.
This used to work fine in CS3 and no other program has this issue. In the OS, all ".indd" files are set to open in CS6. (If I right-click "get info" for an old file and check, it says that it's set to open in CS6.)
If I manually NAVIGATE to a folder using the OPEN dialog box, everything works as expected. InDesign files show up normally and other "unreadable" documents are grayed out and I don't have to enable "All Documents".
Obviously, not a catastrophic error, but certainly inconvenient.