@ AmigaPete
Thanks for your help. I much prefer LHA files as well, but I wish to be able to send zip files to people that are using a PC.
My ZIP button in Dopus is in fact set up exactly the same as yours. At the time of zipping up in Dopus there is no indication of any errors occuring. It is when I use my UNZIP button on the newly created file that I get a lot of reports like 'bad CRC ad79e81 (should be d686bf377)'
However, I have no problem using my UNZIP Dopus button to unpack zipped files that have been e-mailed or downloaded into my PC.
Could you kindly confirm that your UNZIP Dopus button is:-
Amigados SYS:C/UnZip {f}
A4000 Mad