fixed pkzip format (old pkzip).  Now we store both crc and timestamp checksums, and test BOTH inside the format.  If either matches we assume the checksum is 'ok'.  There will be a few more false possitives, BUT there is no other way, since there is no idication of what zip compression tool built the zip, and WHICH of the 2 fields were used.  Also fixed bug where if the decompressed item was 128 bytes or less, we would fail