Backup fails: "The parameter is incorrect (87)."

[buddyman]

Attempt to backup partition causes repeated errors:

! Read disk F: at position 98184568320 failed after 2 attempts. The parameter is
incorrect (87).

These appear continually throughout backup.

OS is Windows Server 2008, partition is 180GB with approximately 70GB used. Command run is:

create /a /o -s="2:2" -a="<path to image file>" -c=9 -u

R-Drive version 4.7, build 4738.

[buddyman]

Also the drive passes SeaTools. I tried to explain this to technical support but my reply was rejected as "spam".