Every once in a while, mostly when lid has been closed on macbook, then opened, when the mac comes back from sleep, an IP configuration warning dialog box comes up. I don't really know what to do to fix this issue. I have a netgear router which my macbook is connected to. That router is plugged in with my hp desktop computer which also gets this exact error as well. Those are the only computers connected to that network. I can still connect to the internet but my pc acts a little weird after that dialog. I would post a screen pic of the warning but it has an IP address and other numbers on it. What it does say is "IP address is here" in use by "other numbers with letters and colons", DHCP Server "another group of numbers with periods, I think IP address" Any help would be greatly appreciated! Thanks!!