[Cube] Internal DVD does not mount

[eiffel at mac.com]

hi list,

this is my configuration :

Cube Powerlogix 800 mhz
built-in DVD reader
external firewire CD-RW
10.3.6 release

today when I put a CD into my internal DVD it does not appear on the 
desktop nor in the finder.
I can use wihout any problem the external firewire CD-RW.

nevertheless if I try to boot directly from the DVD there is no problem.

is tere aroubd someone with an idea about my problem ? system in cause ?

thank you for your help.

Fred