connect over port 80 to windowsupdate.com

I have a problem when smartftp tries to connect to a ssl-server.
everytime i connect to a ssl-server smartftp opens a http-connection on port 80 to www.download.windowsupdate.com.
why is this ?
is this a bug or is it normal ?

i am using windows xp sr1, smartftp 1.0973, german language file.

the firewall atguard is running on my system and states the connection to the above mentioned server is to be established.

can you help me ?

thx