Check the cael folders, and make sure you don't have "folder-in-folder" syndrome. IE: Open the main folder(s) and make sure you don't have a folder exactly like the one you just opened in them, but nothing else (unless, of course, you open that folder). Open the "caelNameplates" folder and you should see two files: "caelNameplates.lua" and "caelNameplates.toc", but nothing else. The "caelMedia" folder should contain eight folders and four files (none of those folders will actually be titled "caelMedia", but two of the files will be). The "caelLib" folder should contain two files: "caelLib.lua" and "caelLib.toc".
You are aware, are you not, that WoWI has it's own installer? Check it out:
MMOUI-Minion