Something in the back of my mind says to format the HD diskettes as low-density on an IBM or an Apple, then try to format it on a 1541.
Supposedly this would rearrange the magnetic particles closer together, to where the 1541 would go ahead and format it..... at least that's what I think I remember.
Has anyone actually tried this? I do not have a 5.25" drive in any of my IBM/MS machines to try it myself, but if I knew it would work I would add one.