If you're one of the early birds who decided to jailbreak their iOS 4.3 firmware without proper Mobile Substrate support, we have good news for you.
A patched version of Mobile Substrate is available that reportedly addresses the issues with ASLR.
As you're aware, the current version of Mobile Substrate doesn't work with iOS 4.3, rendering many of our favorite jailbreak apps and tweaks inoperable on Apple's latest firmware...