Actually, now that I think about it more; a few notes;
My A1000 wouldn't start recently. It had been years in storage since I booted it last. The grease in the floppy drive got harder (i'm guessing) causing it to misalign while loading the disk. I had to have the floppy drive on its side, and/or upside down to get it to boot. after about 30 or so boots, it would finally work reliably right-side-up.
Be sure to use a known good, working floppy for your kickstart. There's not much as far as error checking when loading kickstart from floppy. if it's got bad sectors, hell, if it has a physical hole in the middle of the disk, it might still chug away, loading it into the WCS, without so much as a peep that it had a problem.
The fact that you got the same responses from the A1000 drive and the A500 drive makes me think your floppy media is faulty, or possibly that your drives are all equally misaligned somehow.