Long story made as short as possible.

I tried to install a dvd burner in place of a cd burner on a secondary IDE channel.  Also on that channel was a hard drive whose letter got shifted when the dvd burner was introduced on the same cable.  As a result, XP lost track of where I had set the CD Burning Staging Area path.  As a result of that, I couldn't get Windows Explorer to open CDs\CDRs\CDRWs and view them the way I could view other drives on the system, though file listings were sometimes viewable at the command prompt.  Nor would XP's built-in CD burning features work anymore.  More irritating than these, some applications couldn't find data and a few shortcuts became invalid, pointing to a drive whose letter had gotten switched.  This alone should have been a clue.  After a long and mostly fruitless Google search, I took a serious tour of the Registry and found that the subkey HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders\CD Burning had no value assigned to it.  The default is C:\Documents and Settings\%userprofile%\Local Settings\Application Data\Microsoft\CD Burning, but XP had somehow lost even that information. or at least I had hoped it would fall back to a default.  After typing in a valid drive letter and path (folder name) and restarting XP, the viewing problem vanished.  The rest of the damage had to be undone one application at a time.

I think there is a master/slave issue at work here, though why it came up with the dvd burner, is still a mystery.

Some related things:
    - Burning CDs in Windows XP (Windows Support Center)
    - Description of CD-R and CD-RW recording in Windows XP (MS)
    - CD Burning Becomes Routine in Windows XP (MS)
    - Windows XP CD Burning Secrets (MS)