White Cydia Icon and Safari Crashing When Using Redsn0w 0.9.6b4 to Jailbreak iOS 4.2.1?

After releasing iOS 4.2.1, the dev-team updated redsn0w to version 0.9.6b4 to jailbreak iPhone 4, 3GS, 3G, iPod touch 4G, 3G, 2G and iPad, I received many comments complaining about white Cydia icon and Safari crashing after jailbreaking their devices. Therefore, dev-team has sent...