PROBLEM: cdrecord as normal user broken with kernel 2.6.8.1

As in Object: this has been reported by many user I know, with different chipsets and different IDE cd-burners. Bug wasn't in 2.6.8 rc4.

cdrecord output with kernel 2.6.7 and kernel 2.6.8.1 as root:

# cdrecord dev=/dev/hdc -checkdrive 
Cdrecord-Clone 2.01a36 (i686-pc-linux-gnu) Copyright (C) 1995-2004 Jörg Schilling
cdrecord: Warning: Running on Linux-2.6.8
cdrecord: There are unsettled issues with Linux-2.5 and newer.
cdrecord: If you have unexpected problems, please try Linux-2.4 or Solaris.
scsidev: '/dev/hdc'
devname: '/dev/hdc'
scsibus: -2 target: -2 lun: -2
Warning: Open by 'devname' is unintentional and not supported.
Linux sg driver version: 3.5.27
Using libscg version 'schily-0.8'.
Device type    : Removable CD-ROM
Version        : 0
Response Format: 2
Capabilities   :
Vendor_info    : 'LITE-ON '
Identifikation : 'LTR-52327S      '
Revision       : 'QS0C'
Device seems to be: Generic mmc CD-RW.
Using generic SCSI-3/mmc   CD-R/CD-RW driver (mmc_cdr).
Driver flags   : MMC-3 SWABAUDIO BURNFREE FORCESPEED
Supported modes: TAO PACKET SAO SAO/R96P SAO/R96R RAW/R16 RAW/R96P RAW/R96R

cdrecord output with kernel 2.6.8.1 as normal user:

$ cdrecord dev=/dev/hdc -checkdrive 
Cdrecord-Clone 2.01a36 (i686-pc-linux-gnu) Copyright (C) 1995-2004 Jörg Schilling
cdrecord: Warning: Running on Linux-2.6.8
cdrecord: There are unsettled issues with Linux-2.5 and newer.
cdrecord: If you have unexpected problems, please try Linux-2.4 or Solaris.
scsidev: '/dev/hdc'
devname: '/dev/hdc'
scsibus: -2 target: -2 lun: -2
Warning: Open by 'devname' is unintentional and not supported.
Linux sg driver version: 3.5.27
Using libscg version 'schily-0.8'.
Device type    : Removable CD-ROM
Version        : 0
Response Format: 2
Capabilities   :
Vendor_info    : 'LITE-ON '
Identifikation : 'LTR-52327S      '
Revision       : 'QS0C'
Device seems to be: Generic mmc CD-RW.
Using generic SCSI-3/mmc   CD-R/CD-RW driver (mmc_cdr).
Driver flags   : MMC-3 SWABAUDIO BURNFREE FORCESPEED
Supported modes:

Please note that no supported modes are found. There are many other errors reported with cdrecord -atip or when trying a c2 errors scan with readcd:

cdrecord: Operation not permitted. prevent/allow medium removal: scsi
sendcmd: no error
CDB: 1E 00 00 00 01 00
status: 0x0 (GOOD STATUS)
cmd finished after 0.000s timeout 40s

The same happens with CyberDrv CW088D CD-R/RW and PLEXTOR CD-R W4012A, between the others.