I was able to locate your support message, but its best to include your domain in your post otherwise there is no easy way to match up a forum post with a ticket. I am able to upload files via ftp, https://webftp.dreamhost.com/, and from offsite very quickly. Try uploading from the webftp site as well as trying another ftp program, sftp, passive mode, etc.
The traceroutes submitted show good response times and a double check of the inter-router and network connetions to your server show no saturation. Load on the server is fine, the ftp deamon has already been restarted, etc.
If none of these suggestions work please reply to the support email I have sent so that we can attempt more drastic measures!