3.2 Floppy drive has activity for no rea

We are using our home PC loaded with Win 98 and the floppy drive starts a accessing. There is no disk in the drive and I have not asked to open the drive or save info. After a few minutes it goes away. Then later it happens some more. I have F-Disk the hard drive and done a total reload. I have traded out cables. I have traded out floppy drives. I am at a loss. Please help!
The system is this. Win98/AMDK6II 450 MHZ/128MB SDRAM/13gig wester digital hard drive/52xCDROM/ZIP/CD R/W/R 4x 4x 24x /floppy 3.2/TNT 2 AGP 32MB video card/Space walker mother board.