According to the statistics just 14% of iPhone users have updated the firmware to version 3.1.3.
In particular 72.3% are still using firmware 3.1.2, less than 1% – firmware 3.1.1 and 4.6% have previous versions yet. The reasons for this are probably from the fact that 3.1.3 is only a minor update. Another reason could be the uncertainty of the jailbreak.
The iPhone Dev-Team has released PwnageTool 3.1.5 for Mac OS X. It allows iPhone and iPod Touch users to safely upgrade to firmware 3.1.3. With PwnageTool you can preserve jailbreak and ultrasn0w unlock. But if you’re using the blacksn0w unlock with baseband 05.11.07 you will need to stay at firmware 3.1.2.
PwnageTool 3.1.5 creates a custom 3.1.3 IPSW for the following devices:
Warning! Don’t try to use this tool if you have iPhone 3GS with firmware 3.1.3 – it just won’t work. If you have iPod Touch 1G, iPhone 2G or factory unlocked iPhone 3G , try to use redsn0w – is would be much easier.
You can download PwnageTool 3.1.5. here.