This has come up before but it'll probably be a bigger problem for Fallout 3 modding than it was for Fallout 1/2:

Our file system does not accept large files. I've never got down exactly where it starts rejecting files but it's around 2 MB AFAIK.

Note: it does not actually tells you it rejects the files, annoyingly enough, but they don't end up in our admin list of approveable files. They're just swallowed by the internet.

Solutions:

1. Instead of uploading a file, you can put in a file URL in the text box below the file upload option. This can be any file URL: it can be a link to a Fallout 3 Nexus page, a megaupload link or - preferably - you can register with our filehost Atomic Gamer, upload the file there and use that as the file link. Mirrors and alternate links are also available as options.

2. PM an admin to manually do the upload.