DOS Compatible: CD-ROM Needs To Be In Drive at Startup

I cannot access the CD-ROM from DOS or Windows since I upgraded to version 5.1.1 of CD-ROM Setup on my DOS Compatible Macintosh computer. Everything worked before I did the upgrade and I have not changed anything on the DOS side. What is wrong?
This issue was present with both CD-ROM Setup versions 5.1.1 and 5.1.2. This issue is resolved with the DOS Compatibility 1.5 software update which is available online or for a shipping and handling fee from Apple.

The DOS Compatibility Software Update is a set of software enhancements that improves the reliability and performance of the following:
This update also works with any Power Macintosh 6100 or Macintosh Performa 6100 series computer that has a DOS Compatibility Card installed.

Note: PCI based PC Compatibility cards already ship with the DOS Compatibility 1.5 software and do not need to install this update.

Note: The update is not intended for the Quadra or Centris 610 DOS Compatible computers. Quadra and Centris 610 DOS Compatible computers will need to continue to use one of the above workarounds.

These articles can help you locate the software update mentioned here:

"Where To Find Apple Software Updates" - Lists online services for free Apple software updates.

"Obtaining Apple Product Support in the USA" - Lists 800 numbers and online services for software updates, Apple support information, and a subset of the Apple Tech Info Library.
Published Date: Feb 19, 2012