Here is a good link to dealing with disappearance of CD drives http://users.aol.com/axcel216/xp2.htm#GBYC
Here is a MS Knowledge Base article http://support.microsoft.com/?id=320174
. Today, it seems to be outdated. At least on my system, the IMAPI files are newer than the references ones.
Also, as far as I am concerned, SP1 does improve handling of the CD drives.
NOTE: I've never encountered such situation so that cannot tell if the above works for sure. However, I used to and upon a chance still have a similar problem.
My LS-120 drive is hooked up as a slave on Secondary IDE. After a few hours of the system is running, both drives on that channel get lost. Shutdown and a quarter of an hour rest for the system brings everything back. I think, with some long time of running, area around these drives becomes a little bit overheated.
So, I suggest to periodically check the heating conditions for the F1.
Also, PetDMC, it'd be helpful if you provide more details on your IDE configuration. Sometimes a "clean" connecting of the IDE devices, if you can implement this, helps to narrowdown the problem. I mean, leave just one hard disk on the Primary channel and the CD(RW) drive on the Secondary, while (temporary) disconnecting the rest.
However, I do share with LaffinAssassin the suspection that your IDE drivers may be at fault as well.