The iPhone-Dev Team has just updated their iOS 4.3.1 untethered jailbreak tool redsn0w for iPhone, iPod touch and iPad to version v0.9.6rc12. The update is aimed primarily at fixing numerous bugs and issues with boot animation. If you’re already jailbroken on iOS 4.3.1 with an earlier release of redsn0w, you just need to re-run RC12 over it while making sure you de-selct Cydia in order to avoid any package conflicts. This would fix any boot animation issues you may be having.
Download redsn0w 0.9.6rc12 for Mac
Download redsn0w 0.9.6rc12 for Windows
Also follow our step-by-step tutorial at the following link on how to jailbreak your device with redsn0w.