Unable to read from DVD or CDRW

[Blackbird]

When I first boot WinXP Pro system, I can insert a cd
into the DVD and it will autorun.

If I then insert a CD into the CDRW the CD cannot be
read. And keeps asking for a CD to be inserted.

If I reboot and insert CD into the CDRW it will autorun,
but now the DVD will not read a CD.

Both DVD and CDRW are on Secondary IDE with one as master
and other as secondary.

Occasionally neither will read a CD.

Strangely: When the CDRW cannot read a CD, nor the DVD,
I put in a blank CD which was recognized as blank by the
CDRW, and the recording wizard started up. The DVD could
still not be read. I inserted a CD into the CDR on a
2nd networked computer and read the CD on the first
System.

I then tried to copy the CD from the 2nd computer to the
CDRW on the first system. It ran and successfully burned
a copy on the CDRW. The CDRW could not read the CD but
the new copy was readable on the 2nd system.

After rebooting the new copy was readable on the CDRW.

This is a new phenomena, which started only in the last 3
days.

Does anyone have any ideas???