Hello.

Starting with 2.6.10-rc1-mm4 (or 3),
and now the plain -rc2 has the bug
that causes any process, that is
trying to access my cd-rom, to lock
up.
Jens Axboe suggested it is an ACPI
bug, and indeed, specifying "pci=noacpi"
makes the problem to go away.
Attached are the dmesg outputs from
the functional -rc1 kernel, broken
-rc1-mm4 (note the "lost interrupt"
message at the end), the -rc1-mm4
with "pci=noacpi" log, lspci -v, and
the Alt-PrtSc-t trace of the locked-up
process.
Let me know if something else is needed
to track this down.