Connection reset by peer

[Edgar Rodolfo <rodolfobsd%gmail.com@localhost>]

Hello guys.
Currently i am using:
$ uname -a
NetBSD ns1.netbsd512.edu 5.1.2 NetBSD 5.1.2 (GENERIC) #0: Thu Feb  2
17:22:10 UTC 2012
builds%b6.netbsd.org@localhost:/home/builds/ab/netbsd-5-1-2-RELEASE/i386/201202021012Z-obj/home/builds/ab/netbsd-5-1-2-RELEASE/src/sys/arch/i386/compile/GENERIC
i386

when i am using pkg_add i can install some package, but when i stop
three minutes
pkg_add -v, says:

ns1# pkg_add -v gimp
pkg_add: Can't process
ftp://ftp.netbsd.org:21/pub/pkgsrc/packages/NetBSD/i386/5.0/All/gimp*:
Connection reset by peer
pkg_add: no pkg found for 'gimp', sorry.
pkg_add: 1 package addition failed
ns1#

I want to know what is the problem? how can i  fix it? i want to
continue to install more software..., thanks in advance!