It turns out that the long delays I sometimes experience when trying to open or save a document — the application hangs for several seconds — is due to issues with iDisk syncing: “The problem lies in the fact that the local iDisk (stored in /Volumes/iDisk) has symbolic links (aliases) to folders on the remote iDisk (/Volumes/your_mac.com_name). When OS X lists the local iDisk’s contents, info for these folders must be loaded from the remote iDisk, which can take some time.” For some reason I assumed it had something to do with the external hard drive I bought last fall.