Two reasons this could happen.
1. The author isn't sending the files. Thus Make sure you adjust the setting in Dial Dictate "Send files if author hangs up" to be checked. Also , under record menu keys make sure that there is a key available to "Send and Hangup" and have the authors use that key
2. This can also happen if your FTP settings have changed and the software isn't moving the files. To overcome this recheck your settings and firewall.
If some of the files are getting through then it's most like the first reason.
If none are getting through then it's the second reason.