i was about to add this tweak but ti says it can crash your iphone so just wanted to make sure

If the developer says it doesn't work, I wouldn't chance it. That said, the initial reason that most devs had glaring statements about 4.0.2 was that in the JailbreakMe era, you couldn't jailbreak 4.0.2 -- they put 4.0.2 out specifically to address the JailbreakMe PDF exploit, as well as one or two minor things. If you have a safe backup, all your SHSH's on file, and don't mind getting your hands dirty, it's worth a shot -- you may find it works just fine. Alternately, it may crash the hell out of your device, bootloop it, and force you to restore -- so if you don't have the SHSH's you'd need to dig out of an unfortunate bootloop, I'd stay away until the author says it'll work.

Originally Posted by ak786

i was about to add this tweak but ti says it can crash your iphone so just wanted to make sure

The developer of this tool seems to note that his tweaks are very dependant on the kernel patches applied to jailbreak. This means that not all jailbreak tools are created equal. Many don't bother to properly handle all the required kernel patches.

In your case.. I would recommend you update to 4.1 or if you *must* stay with 4.0.2 use redsn0w 0.9.6 beta 2 or beta 3 (with a 4.0 IPSW) or limera1n to jailbreak (yes I rarely recommend limera1n but it is one of the few tools to jailbre 4.0.2 and bundles the correct kernel patches).

The warning message you referred to was written before the limera1n/comex exploit was released that allowed 4.1 to be jailbroken untethered.

Even then I would suggest that you have a 4.0.2 SHSH on file before you attempt this.

well i jailbreaked using limerain, well when i go to infiniboards or infinidock in some sources it doesnt say anything about crashing where as in one source it says it cause to crash. and i didnt backup the shsh so i jus dont wana risk crashing my phone