New ASUS board will not Hot Plug ESATA Drive

I have a WD 500GB SATA external drive in a Nexstar 3 case. This was connected to my ASUS A8N5X mother board. I was able to hot plug this drive all the time just by turning the drive on and off via the power switch on the back of the Nexstar case. Very convenient, considering I only use this for back ups etc. I just upgraded to a new ASUS board, an M3A78-EM. It will not allow me to hot plug. I must boot up with the external drive on. It is connected to the ESATA port, I have tried to set the SATA Configuration for AHCI but the system will not boot up. I am using XP Pro SP3. I even tried connecting it straight to one of the SATA ports on the board instead of the ESATA port but still no hot swapping. Why did my old Mo-board work just fine and this one doesn't? Am I missing something? I hope someone has an answer for this one.....Thanks in advance, Kevin.

Try right click my computers/properties/hardware tab/device manager -> scan for hardware changes.

This works for me on the new boards.