Dont update on 4.3.5 because there is no untethered jailbreak available so if you dont know the diff between UNTETHERED AND TETHERED JAILBREAK :
What is Tethered Jailbreak :
Tethered jailbreaks are frustrating because they require a computer connection to boot a jailbroken iOS device. The concept of a tethered jailbreak has been around a long time, but essentially it means this: every time your iPhone or iPod touch reboots or the battery dies, you have to connect (tether) your iOS device back to your computer so that the hardware can boot with the aid of the jailbreak application
What is Untethered jailbreak ?
An untethered jailbreak is the preferred jailbreak because it requires no connection to your computer except for the initial jailbreaking process. You can reboot your iPhone or iPod touch as much as you want without having to tether it to your computer to boot. If the battery dies on a device that has an untethered jailbreak, it’s no big deal you just charge it again and it will boot as usual.