anyone have problems with the F400 D2 Dual layer DVD burner? sometimes it mounts and sometimes it just doesn't, I have it daisy chain to a HD and most of the time when I connect the HD, the D2 mounts. However, recently the D2 did not mount even with the HD mounted. Tried, reseting, shut up and restart but no luck. I was able to burn a DVD before this happen. I had this issue 2 months ago and now is back. is it the Book's problem, the OS or the D2's?