dvd-drives:no media [11.3, 64bit]

Hi,

I just noticed that I can no longer use my dvd-drives (one sata drive and one ide-drive) under 11.3, 64 bit, 2.6.34.7-0.7-desktop)

the drives themselves are recognized, but if I insert any media (eg. empty dvd or audio cd) it is not detected.
if I call eg. k3b or vlc, they report: no media. as well no reaction in the panel.

if additionally have one old scsi cdrom drive in the computer that works.

any ideas about the reason or any solution?

thanx
paul