Strange Optical drive problem

[squareyes]

Hi all,
have posted this problem before, may some new info.

Machine Lenovo 0687  Optical drive will work OK to install both WinXP 
and Ubuntu 8.04,
but once systems installed no longer exists. Will not read any CD's 
after install in both XP or Ubuntu,
but will still look at bootable Disks after either system  installed, 
e.g. will run live gparted cd. Knoppix.
Any ideas much appreciated, Lenovo's only suggestion was to update bios, 
which I have done.

Many thanks in advance
Take Care
Winton