That is weird. So, everything worked before between Amiga and PC then stopped working, and Amiga to Amiga still works? You haven't made any changes to your ZIC: device, or to your CrossDOS handler, correct? I have had problems with Zip drives and CrossDOS before, but this particular issue is not familiar. That you can read and write on the Amiga would indicate to me that it's not write-protected -- I don't believe Zips differentiate between writing and formatting.
