If you are trying to upload files and then they seem to disappear this could be caused by a virus/Trojan in the file. All file uploads are scanned for malware, viruses and Trojans. We quarantine those files so we can check and see if that is the case. Because of the Gumblar attacks, we enabled virus scanning of all uploads. The Gumblar infects a persons computer and uses their FTP credentials to upload a Trojan.