For zip files, you should set the proper file type.
For example:
$anonUsersFiles=array(
...
'application/x-zip-compressed'=>102400,
'application/zip'=>102400,
...
);
the same for
$regUsersFiles.
Note that registered members and guests could have different privileges in uploading different file types of different file sizes. But the standard definitions are the same for both.
Both 'application/zip' and 'application/x-zip-compress
ed' should be set for zip files, because various browsers may send this or that header identifying such a type.