sysinstall fails to fetch; pkg install succeeds

[Gary Aitken]

I'm in the process of installing a 9.3 system.

"pkg install foo" seems to work fine, fetching from the network.
However, if I run sysinstall (forgot to include the handbook), it fails
when trying to fetch from the network.  I've tried both FTP mode and
FTP through firewall mode.  What does sysinstall do that's different when 
trying to fetch from the network?

This is going through a firewall running natd and ipfw, so it may be a
firewall rule problem.  But I would have thought they would either both
fail or both succeed.

I've tried several different fbsd ftp sites, including the main one.

tcpdump fragment:

IP 192.168.17.3.31940 > 204.152.184.73.21: P 289:311(22) ack 863 win 1040 <nop,nop,timestamp 3395359 2714296683>
IP 204.152.184.73.21 > 192.168.17.3.31940: . ack 311 win 256 <nop,nop,timestamp 2714296740 3395359>
IP 204.152.184.73.21 > 192.168.17.3.31940: P 863:889(26) ack 311 win 256 <nop,nop,timestamp 2714296740 3395359>
IP 192.168.17.3.31940 > 204.152.184.73.21: P 311:340(29) ack 889 win 1040 <nop,nop,timestamp 3395422 2714296740>
IP 204.152.184.73.21 > 192.168.17.3.31940: . ack 340 win 256 <nop,nop,timestamp 2714296806 3395422>

Looks to me like it should be working?

Thanks,

Gary