While using our 8510C (SX option) and the 'Agilent 8510 Specifications And Performance Verification Software', part no 08510-10033 (Rev.A.05), to perform the calibration of a calibration kit, the program indicated a 'disk read error'' when it tried to read the verification kit floppy disk. Our analyzer will no longer read any of our verification floppy disks, however it will read our calibration kit floppy disks. I have tried using a number of different verification disks, I also replaced the disk drive, no help. I ran the tests for the A7 IO card disk drive function in the system service program, they passed. Has anyone any idea on this ?