CDROM is not recognized in certain configurations

Tested on VirtualBox version 3.1.0, ReactOS r44453 (self-compiled), r44557 (from build server).

CDROM device is not recognized if it and HDD are both attached to the same IDE channel. There is a pause after loading 'UNIATA.SYS', when booting (no pause, however, when CDROM is a master and HDD is a slave device on the primary channel).

From the log:

(ntoskrnl/io/iomgr/driver.c:1391) '\Driver\Cdrom' initialization failed, status (0xc000000e)
(ntoskrnl/mm/sysldr.c:198) 2 imports not dereferenced!
(ntoskrnl/mm/sysldr.c:201) class2.sys <class2.sys>
(ntoskrnl/mm/sysldr.c:201) multi(0)disk(0)rdisk(0)partition(1)\ReactOS\system32\drivers\scsiport.sys <scsiport.sys>

When uniata.sys is replaced by atapi.sys, there is also such a pause (including that aforementioned special configuration), but after that CDROM works well.