Imaging Toshiba portege!

I am trying to do a multicast imaging session with a laptop being the the
master and 6 being the clients. I am running into a problem were the
laptops are imaging real, real, but real slow. I mean, I left them
imaging yesterday and they are still at 75% imaging, it is ridiculous. I
have the ZCM server as a virtual server in ESX with a 1G connection. I've
image before different kinds of computers and they are imaged in 20
minutes or less. I want to know if I need to do anything in the switches
side or in the server side. I am running ZCM in a windows 2003 server.
Any help will be greatly appreciated.

Thanks,

Horacio