Permissions Issue With Folders

I had the Ultra 6 set to everyone read/write and loaded a ton of folders and files onto a new share. Afterwards I gave everyone read-only access to the share and created 2 named accounts with read/write access. The problem now is that the named users can attach to the share and can create new folders and files but cannot write to the folders that were initially loaded. Do I need to do some kind of permission change on the existing folders/files ???