I use scsi emulation and usually my dmesg has this:
scsi0 : SCSI host adapter emulation for IDE ATAPI devices
Vendor: SONY Model: CD-RW CRX220E1 Rev: 6YS1
Type: CD-ROM ANSI SCSI revision: 02
sr0: scsi3-mmc drive: 246x/52x writer cd/rw xa/form2 cdda tray
Uniform CD-ROM driver Revision: 3.20
Attached scsi CD-ROM sr0 at scsi0, channel 0, id 0, lun 0
now the last line is gone... .. and i can't use my cdrw because ..hell .. "it isn't there".Anyone knowing what's this prob about ?
(just to make this clear: my sr0 doesn't apper to be a valid device)
thanks in advance

Maybe you've got other (real) SCSI devices plugged in? I had trouble on a system with a SCSI hard drive and two IDE CD-RWs, until i found that they were 1,0,0 and 1,1,0.
-trainpic

no.. i'm quite sure i haven't got any other scsi devices...
it worked fine until now....but now it changed his mind

Maybe you need this added to you're grub kernel options:
hd[I]x[I]=ide-scsi

where [I]x[I]=
a for master ide 1
b for slave ide 1
c for master ide 2
d for slave ide 2

also, humor me and see if the connector fell out

-trainpic