Ok, I'm having the exact same problem as in this question http://serverfault.com/questions/59635/outbound-ftp-on-server-2008-r2-stalls but the accepted answer didn't help me much...
I followed the third step of this http://learn.iis.net/page.aspx/309/configuring-ftp-firewall-settings/ guide in order to configure my firewall for FTP, and I am able to authenticate, however, the data channel doesn't seem to be passing through the firewall. If I disable the firewall, everything works fine. Hope someone can help me, as this is really starting to annoy me.
Best regards,
x3ro