Thanks very much for your input. However, as I indicate in my original post, I had already tried repeatedly to disable IMAPI in Windows XP (using the method you described) and then reinstalling InCD but without success.
I had occasion to reinstall XP during the weekend and this time I disabled IMAPI before installing Nero Express, InCD and EasyReader. This worked because the blank disks previously formatted now displayed as FS-UDF instead of UDFRDR. So this problem has now been solved. My guess is that previous attempts at uninstalling InCD prior to disabling IMAPI were not successful.
The downside is that disks previously mounted and written with InCD on a Windows 98SE pc now show folders with no content. I have a nasty feeling that reinstalling Ahead's generic UDFReader will reverse the present situation by allowing me to read from the older disks (which will probably display as UDFRDR) but prevent the formatting blank media with InCD. Sigh.........!!!