Definitely NOT a fine tuning issue
I would check DNS setup and performance on all linux/unix systems involved in the ftp. DNS hang is one thing you want to either rule or rule out first. Can try pinging by name and also dig command. CHeck out /etc/resolv.conf and /etc/nsswitch.conf. resolv.conf should just have a couple of lines specifying the IP address of primary and secondary name servers to use. look at nsswitch.conf and make sure hosts: line
is something like hosts: files dns
If still having stalls after rechecking everything DNS, then you can try running strace -f -o /tmp/strace1.out ftp <wherever>
strace will print out the system calls made to /tmp/strace1.out (you can call the file whatever you want, it will just be a plain ASCII file)
strace -f -o <output file> <command>
If looking look near the end of the output file and look for system commands that tend to take more time ( bigger increments in time between system commands) or perhaps be called more frequently.
If still can't find anything then would try to check if there is any possibility of connection problems in any way.
Also be sure to look over /var/log/messages with a fine tooth comb.