I have a MacBook Pro C2D and a 12" Powerbook and my wireless network runs on a Motorola SBG900 using WPA for security. I'm having an issue where, every time the 12" Powerbook joins the network, my MacBook Pro is disconnected from the wireless network and displays the following message: "The wireless network appears to have been compromised and will be disabled for about a minute." After this, I cannot reactivate the wireless connection for a minute and on some occasions it will not reactive at all. I am using DHCP and have allocated enough IP's and allowed the MAC addresses for both machines. I've also had no problems when sharing the network with a number of Windows laptops and the Powerbook, but the MacBook Pro is always kicked off. Has anyone experienced this problem, is it possible that there is some conflict between the laptops regarding IP, MAC, WPA Protocol. And does anyone have any tips on how to debug this? Searching google for this exact phrase only returns 2 pages of results, there is a site with a screenshot of the dialog box, which looks like this. Any help much appreciated.