GreenPois0n RC5 on Mac OS X Leopard

Many people, myself included, have been trying to get the new version of GreenPois0n that provides an untethered jailbreak on iOS 4.2.1 to run on Mac OS X 10.5.x without luck.
The application would open and then close immediately, and provided no indication as to why.
So I did a little digging and some Googling.
Checking Console.app:

Click for Enlarge it !

Looks like it was libcurl.4.dylib that GreenPois0n is calling, and it looks like it�s calling version 6.0.0, but getting 5.0.0 and then closes out when this happens.
A few Google  searches later and I found what I needed, and it worked perfectly. Here�s the solution if this is your issue:
1. Download this file: libcurl.4.dylib v6.0.0
2.Extract the file in your downloads folder.
3. Launch Terminal.app
4. Type: sudo rm /usr/lib/libcurl.4.dylib
5. Enter password and hit enter.
6. Type: sudo cp ~/Downloads/libcurl.4.dylib /usr/lib
7. Close Terminal.app and launch greenpois0n.app
8. Enjoy.