Program to unzip corrupt zip files?

I get a lot of corrupt zip files from customers - and sometimes they contain multiple files and they have to resend everything because the zip file is corrupt.

Is there any software out there that will extract as much as possible from a zip file that is corrupted? If it can get 19 out of the 20 files that were zipped, that would be great. If it's only one file that is zipped and it's corrupt, well, that's that.... But even if it can pull it out of the archive, I can see if I can make use of it...

All I use right now is the unarchive utility through Finder.

Thanks,
Jon

zip file Error 1 Message

I am new to posting so bear with me if I have placed this in the wrong place.

I downloaded jpegs from mobileme and they were put in a zip archive. When I tried to open it (OSX 10.6.4) I got a message " Unable to archive ".......zip" into "Desktop" (Error1 - Operation not permitted.) What does this mean? Is the file corrupted? can I save it?