I have a network running Cisco 2900 switches and Cisco fasthub 400's. When attempting to copy files from one IMac to another ( using Apple's Network Assistant) I keep timing out and losing my connection. I can copy a few files before this happens. HELP. I've got about 140 IMacs that need to be imaged. I can copy files from one to the other if I use a cheap little 10mb hub. What's wrong with the Cisco stuff?