The plugin uploads the file to the publish server and then reports

ERROR: Failed to upload files
java.net.SocketTimeoutException: Read timed out
at java.net.SocketInputStream.socketRead0(Native Method)
at java.net.SocketInputStream.read(Unknown Source)
at java.net.SocketInputStream.read(Unknown Source)
at java.io.BufferedInputStream.fill(Unknown Source)
at java.io.BufferedInputStream.read(Unknown Source)
at java.io.FilterInputStream.read(Unknown Source)
at java.io.PushbackInputStream.read(Unknown Source)
at org.apache.commons.net.io.FromNetASCIIInputStream.__read(FromNetASCIIInputStream.java:75)
at org.apache.commons.net.io.FromNetASCIIInputStream.read(FromNetASCIIInputStream.java:170)
at java.io.BufferedInputStream.fill(Unknown Source)
at java.io.BufferedInputStream.read(Unknown Source)
at org.apache.commons.net.telnet.TelnetInputStream.__read(TelnetInputStream.java:114)
at org.apache.commons.net.telnet.TelnetInputStream.run(TelnetInputStream.java:535)
at java.lang.Thread.run(Unknown Source)

And sets the Buildjob always to unstable. But the file was received successfully by the server:

Entry from xferlog:
Wed Feb 19 10:41:48 2014 5 xx.xx.xx.xx 4192181 /srv/ftp/upload/jenkins/xxxxx/xxxxx.tar.bz2 b _ i r ftp ftp 0 * c

Entry from the access.log
xx.xx.xx.xx UNKNOWN ftp [19/Feb/2014:10:41:48 +0100] "STOR xxxxx.tar.bz2" 226 4192181