II recently sent a file "zipped" by "Make Archive" in the Finder to a Windows user. She could not open it. I zipped it again using Stuffit v9 and she had no trouble. Yesterday I downloaded two zipped files from Inkjetmall and neither the Finder nor Stuffit could open them though I have had no trouble with files from them in the past. They finally opened using "Panther Unzip". What is the score here, all the files had similar icons and visible attributes as far as I looked. It rather defeats the purpose of a universal(?) format if it is touchy. I never had any trouble with Stuffit files but then they are Mac only and the Windows mob have not had a chance to screw it up.
Maybe I am being overly harsh?

I haven't quite figured out the problem yet, but I have also noticed it. Additionally, I've found that some zip methods totally screw up the file, even changing the final file size. Three main methods are using "Archive" from OS X, Stuffit's zipping, and gzip from the terminal. I use the UNIX gzip utility the most as I've had the fewest and least issues with it. Will report back if I figure it out.
Andrew