I noticed this on the last server I moved from, and again tonight when I tried to move 20 odd accounts.
The time out value in ssh, by default, I think is 2? minutes, so if the pkgacct process takes longer than 2 minutes, it times out.
The pkgacct process carries on on the source server and the destination server restarts the process again, thus, starting yet another pkgacct process.
Tonight I noticed there were 5 pkgacct processes for the same (largish) domain, which actually ended up killing my source server.
I'm still waiting on BurstNet to find out what's gone wrong, but it's been inaccessible for an hour now, heh.