VsFTPd Multiple File Upload whoas

Hello!
I am using vsftpd as my server on my Ubuntu machine. I am behind a linksys router. I am trying to upload a massive amount (several thousand) of files using a program I wrote in java which implements enterprisedt's edtftpj. The purpose of this is to perform a differential back-up of my laptop. This code all worked fine when I was behind a different router (provided by verison).

I connect to the server from the client and begin uploading files just fine. Sometime though the uploading process (usually about 20 minutes after the uploads start, I get disconnected from the server and all subsequent uploads fail.

I know you need additional information. Please let me know what is needed.

Thanks!
Jeff

The error that Im getting is:

When I changed to the Apache Commons Net library, I get this error:
java.net.SocketException: Connection reset by peer: socket write error