FTP option ftp_epsv

[Nil Nik <nil_fergi@xxxxxxxxxxx>]

I have configured browser (http and FTP option) to use squid proxy.
some FTP sites are opening with the help of browser but not "ftp://ftp.uar.net/";

If i use "ftp_epsv off" then it works fine.
I am using squid-3.1.9.

What was the exact problem?
Please tell me consequences of "ftp_epsv off".
Does it will affect on some other settings?

Thanks in advance!!!