I use an ATEN CubiQ CM0264 KVM Monitor Switch. Mouse and keyboard is switched and passed thru an USB connector of the KVM. When the USB connector is connected to the DH87RL boot hangs. I have to disconnect the USB port pass the boot scan and boot starts. After that I can reconnect the USB to gain access with mouse and keyboard. Problem occurs with old and the newest BIOS (323). Other systems connected to the KVM do not show this problem. With direct connection of mouse and keyboard the system boots without a problems. Any suggestion?
I am sorry to hear you are having problems. Can you please post your dxdiag report here?