When scanning the drive in question -> 750 gb, partitioned using ranish, formatted with format.com (04/23/99), with 16kb cluster size and 45.76 million clusters:
Dos scandisk from win-98 (04/23/99) ran all tests in about 2 or 3 minutes, but put up the message that it couldn't perform a surface scan because there was not enough conventional memory (this was while booted directly into DOS). Free memory was 604,xxx bytes. After modifying config.sys and autoexec.bat to get memory up to 633,xxx bytes, scandisk did not display that message. It estimated it would take 3.5 hours to perform a full surface scan. I told it to start the scan, and after about 1 minute of inactivity, it brought up the screen showing the drive map and began the scan. I stopped the scan after a few minutes.
When scanned by Norton Disk Doctor (from NSW 2002), NDD ran through the first test (partition table) and got partially into the second test (boot record) before throwing up a blue-screen error from which the computer could not recover from, requiring a cold re-start. I have the NOLBACHECK registry entry set for Norton Utilities, but it didn't help.
I was under the impression that after a drive is partitioned (using fdisk or other programs) that the cluster-size is not set during the partition process but that format.com has complete control or freedom to choose the cluster size. I will perform a re-partitioning of the drive and try to set the sectors-per-cluster (as described here: DOS Boot Sector) before attempting a re-format.