FTP Problems after upgrade

I've been using the personal version for a couple of years now and have never had any problems. About a week ago I was propted to upgrade because the current version had expired. After I upgraded my FTP connections stopped working. I get this message when I try to connect.

SmartFTP v1.5.991.31
Resolving host name "host.server.com"
Connecting to xx.xxx.xxx.xxx Port: 21
Connected to host.server.com.
220 host FTP server ready


Any ideas What could be causing this.

I'm running Win XP SP2 with Zonealarm 6.0...

Thanks.

In any case, please switch to SmartFTP 2.0 and try again, version 1.5 will soon not be supported any further (for non-paying customers).