Hi everybody,
I'm pretty new to this and really not-experienced as a Linux user but I
couldn't find an answer elsewhere (f.a.q., other boards, etc.) so I hope
someone won't find this annoying.

My problems: the system recognizes the soundboard (system soundfiles are played, etc.)
but I can't play audio-CD on both the installed units (which are perfectly working as data-reading units).

I hope I'm forwarding enough info.
Any help will be more than welcome.

the units:
hdc: TOSHIBA DVD-ROM SD-R5002 ATAPI CD/DVD-ROM drive
hdd: GCR-8521B, ATAPI CD/DVD-ROM drive

output from /sbin/lspci:
00:00.0 Host bridge: nVidia Corporation nForce CPU bridge (rev b2)
00:00.1 RAM memory: nVidia Corporation nForce 220/420 Memory Controller (rev b2)
00:00.2 RAM memory: nVidia Corporation nForce 220/420 Memory Controller (rev b2)
00:00.3 RAM memory: nVidia Corporation: Unknown device 01aa (rev b2)
00:01.0 ISA bridge: nVidia Corporation nForce ISA Bridge (rev c3)
00:01.1 SMBus: nVidia Corporation nForce PCI System Management (rev c1)
00:02.0 USB Controller: nVidia Corporation nForce USB Controller (rev c3)
00:03.0 USB Controller: nVidia Corporation nForce USB Controller (rev c3)
00:04.0 Ethernet controller: nVidia Corporation nForce Ethernet Controller (rev c2)
00:05.0 Multimedia audio controller: nVidia Corporation: Unknown device 01b0 (rev c2)
00:06.0 Multimedia audio controller: nVidia Corporation nForce Audio (rev c2)
00:08.0 PCI bridge: nVidia Corporation nForce PCI-to-PCI bridge (rev c2)
00:09.0 IDE interface: nVidia Corporation nForce IDE (rev c3)
00:1e.0 PCI bridge: nVidia Corporation nForce AGP to PCI Bridge (rev b2)
02:00.0 VGA compatible controller: nVidia Corporation NV11DDR [GeForce2 MX 100 DDR/200 DDR] (rev b2)

messages I get from the system log when I play an audio-CD (which is being actually played by the cd-player, but I can't hear anything):

localhost modprobe: modprobe: Can't locate module sound-service-0-0
localhost modprobe: modprobe: Can't locate module sound-slot-1
localhost modprobe: modprobe: Can't locate module sound-service-1-0
localhost modprobe: modprobe: Can't locate module sound-slot-1
localhost modprobe: modprobe: Can't locate module sound-service-1-0
localhost ntpd[2306]: kernel time discipline status change 1
localhost modprobe: modprobe: Can't locate module sound-slot-1
localhost modprobe: modprobe: Can't locate module sound-service-1-0
localhost modprobe: modprobe: Can't locate module sound-slot-1
localhost modprobe: modprobe: Can't locate module sound-service-1-0
localhost kernel: cdrom: open failed
localhost kernel: SCSI cdrom error : host 0 channel 0 id 0 lun 0 return code = 28000000
localhost kernel: ILI Current sd0b:00: sense key Illegal Request
localhost kernel: Additional sense indicates Illegal mode for this track
localhost modprobe: modprobe: Can't locate module sound-service-0-3
localhost kernel: cdrom: This disc doesn't have any tracks I recognize!