P4C800-E Deluxe Losing Optical Drives

Hi,
My P4C800-E Deluxe periodically loses all my optical drives and the only fix is to power off hold down the insert key and power up again. I have tried various bios and am currently running 1014 bios previously using 1011 where I had the same problem.

Sometimes in windows (XP Pro) my optical drives are missing also.

Please can anyone shed any light on my problem?

thanks in advance