zip files expand to a zip.cpgz


I've downloaded a .zip file, if I double click on it, a zip.cpgz file is produced. If I click on that, it produces another .zip file.
I've seen this problem on many a forum, and I've tried many of the suggestions eg

Update Stuffit - I've used Stuffit 2010 and it comes up with this error:
"Unspecified Stuffit Expander Internal Error (Error #17999)"

I tried iArchiver - nothing

I tried The Unarchiver - nothing

I tried the free version of Springy - it did something ie I could see folders in the background, but then it said the file was too big.

I'm running Leopard

I'm despairing at present. Any suggestions welcome.


Maybe the .zip file is corrupted - or is an invalid format, either damaged, or not a correctly zipped file at all. Could be a virus-infected file, that your Mac doesn't recognize, and would trigger a virus/etc alert on Windows.

Do other, different .zip files still work OK for you? If so, did you simply try downloading that same file again?