Brand new C2D-based iMac running Leopard. When my computer is awakened from sleep mode, it cannot find my router, and I have to manually connect every time. I am connecting via wireless to a D-Link DGL-4500 with the SSID hidden. I am on the 802.11a/n band. I went into the network connections setup on this Mac (Advanced|Airport), and my router does show up, but I have to manually connect it every time. I've tried removing the entry and readding it, but it doesn't help. Any thoughts?