I occasionally get reports of problems between Default Folder X and Adobe InDesign. One user has done some digging and found that InDesign has some pretty major, known problems with Leopard’s Navigation Services (NavServices is the part of OS X that provides the Open and Save As dialogs). You may get crashes in InDesign when running Leopard, regardless of whether you’re using Default Folder X or not, and unfortunately, they’re not things that I can fix in DFX. For more details, see:
Thanks to James Wondrack for tracking down this info.