I had the misfortune of having a CD burner which did something that
forever caused grief on the IDE bus as its way of checking the status of
the tray. If there was no disc in the tray, it'd do something every now
and then to see if one was, then, in the tray. Even after you put a
disc in, it'd still do something similar.
If you get problems of that nature please file a bug against the "hal"
component and stick me on the cc (in case its kernel). You can tell which
it is by booting single user "linux s" and seeing if it plays up or only
when HAL starts in multi-user mode.