There are few things to watch-out for in WDAD. First, double-check your folder structure for the mod in the MODS folder. It almost sounds like you might have a 2nd WDAD mod folder. You want "GameFolder \SH4Folder \MODSfolder \WDADfolder \DataFolder|" with each of those "folders" representing your actual folder names. Depending upon the zip utility used, and how you use it (why does that sound familiar??), you might end up with "GameFolder \SH4Folder \MODSfolder \WDADfolder \WDADfolder \DataFolder|" instead.
Another thing, make sure that you do NOT have the game installed in a "Program Files" Windows folder, such as "C:\Program Files (x86) \Ubisoft \Silent Hunter Wolves of the Pacific" structure, or similar. Older games such as Silent Hunter and JSGME are not "authorized" sources of changes in the Program Files folders, and Windows UAC will rollback all edits performed in that folder. You need the game installed in a folder structure of your own creation, such as "C:\Games \Silent Hunter..." or similar. You do not want to put the game folder directly in the "root" of the drive, for that just-in-case scenario... such as the first paragraph...
