I upgraded today, using Recovery Mode, to 3.1 on my iPhone 3GS using the new PwnageTool. There are a couple quirks that stuck around from when I was on 3.0.1, i.e. my battery percentage indicator is inaccurate for some bizarre reason. I didn't restore from a backup. I have tried calibrating the battery a couple times over the past month by draining it to 0% and then letting it charge back to 100%. I've done the "Reset All Settings" in the Settings app. I've tried everything to fix it short of a DFU restore. Just telling you this so you don't suggest for me to do one these things. So, the actual question.. is it possible to DFU restore to jailbroken 3.1 when I am already on 3.1 and jailbroken? It may seem like a stupid question, but I don't want to run into any problems that may force me to officially update to 3.1 and lose my jailbreak. P.S. Battery info, if anyone cares- It's inaccurate in that it hangs on 100% until the actual level is 96%. Then it drops to 99% and continues to be 3% higher than what both the Free Memory app that used to be in the app store and the battery indicator apps from Cydia tell me. It then gradually starts to become more accurate as the battery level drops; at about 40 to 50%, the indicator is only 2% above. At 10 to 20%, it varies between being the same, 1% above, or 2% above. I'm thoroughly confused as to why my indicator is inaccurate. I have a 3GS and didn't modify it in any way to get the percentage.