cdRom not showing up sometimes until system is put to standby/Start

[cganti]

i have a very good PC ,P4,3.06Ghz system and evrything works fine but has a small problem, after starting the sytem we can see all the drives( i have one DVD+RW drive and CDRW drive)
and i can put CD in them and use them but i dont know when it happens,sometimes i cant see any drive other than C drive,then i will make the system to go to standby for few seconds and come back then i can see the drives. Or if i shutdown and restart also i can see the drives?
can anybody tell me what might be the problem???
thankyou
ganti

 

[Lemon13]

it might be acpi/apm. disable in bios/windows 2 check.

 

[satrow]

Sorry, Lemon13 but I feel it's a little hasty to rush straight into that; if it doesn't cure the problem it will take a reinstall to reinstate it.
This is a new machine, has it always done this or is it recent?
Check in Device Manager and tell us what, if any devices share an IRQ (right-click My Computer - Manage - Device Manager - View - Resources by type - IRQ).
While you are in the management console, go to the Event Viewer - System - View - Filter - remove the ticks from Information and Success Audit -click OK and check for any messages at the times that this happens; also look for specific messages relating to IDE/Atapi/ATA, CD Rom etc., anything that could be related. Do the same with the Application Event Viewer.
Which order are your optical devices listed in the Device Manager (default view)- IDE ATAPI controllers? On the secondary channel, or one on the primary? Check the properties - Advanced settings that they are both DMA enabled.
Are you using XP?
Report back to narrow it down.

Andy.