Version 4.51 beta 2007-07-25
- Bug was fixed: 7-Zip 4.50 beta could not open some .7z archives.

Version 4.50 beta 2007-07-24
- New switch for command line version:
-ssc[-] enables/disables case-sensitive mode for file names.
- Speed optimizations for AES encryption.
- Some bugs were fixed.