os x has the concept of 'file wrappers'. these items appear as files form the finder, but are actually a directory with x number of files as viewd from the underlying shell. this are often used to allow attching one or more files to a base content file (for those that aren't familiar). the file upload dialog in both safari and firefox allows you to select these file wrappers when adding content to alfresco, but then both browsers crash or hang when attempting to actually do the upload. have you encountered this at all?