Freeze when doing site-to-site

[PaulB]

I'm trying to transfer files between a remote Cobalt RaQ3 and a RH 7.2 machine with Plesk.
Here's my proftpd.conf's
RH 7.2:
<Global>
DefaultRoot ~ psacln
AllowOverwrite on
AllowForeignAddress on
</Global>

RaQ3:
<Global>
AllowChmod on
# Report localtime, not GMT
TimesGMT off
AllowForeignAddress on
</Global>

I can connect to both sites fine, but when I start a site-to-site transfer, it creates the first file/directory on the target site, but never transfers it or anything else. The size remains 0...FlashFXP just hangs there. So I have to disconnect and quit.