I wet to the Zenithink site and downloaded the 4.0 version. I tried the xxxN3xxxx version since i wasn't sure which one I owned. They say in the instructions that if you install the wrong version for your tablet that the camera won't work and to just reinstall the other version. The problem is, my tablet camera worked on both versions, so i believe they are incorrect. This fooled me in to thinking I had the right version. But the first time I shut it down, it would not boot back up unless I pushed a pin in the reset hole4. I would boot and work fine then, each time. This was driving me crazy since my camera worked so I assumed I had the right version. So I figured it must be the 4.0 version, so I just downloaded the latest 2.3.4 version, but again, the xx3nxxx version thinking it was the right version. I installed, it and was really sacered when it still would not boot without using a pin to the reset hole. Again, once it booted, it worked fine and the camera worked fine. So then I thought I would try using the factory reset in the menu, so i did that, erased me sd card, then told it to do a factory reset. but this was strange. It did the factory reset, but it still loaded up with the latest 2.3.4 xxx3nxxx system. The front scree was not the same as the version it had when i got the tablet. The version date when I had the tablet said it was from September 2011, t6he reset still said it was 2.3.4, and there's really no way you can mess up the factory reset because you simply tell it to proceed, and it does and reboots. So i believe that when you load a new 2.3 version, even the factory reset uses that new version. In the September version that was on the tablet when i got it, the app button was at the bottom, and when you hit that, brought the applications up, then swiped your finger the application animation shows the large square with all the apps as it turns. In the new version 2.3.4, the app button is on the right, and you hit it, and then swipe your finger and the animation is now a circle, like a world shape. So the thing is, when I did the factory reset, it DID NOT go back to the September or before version, it stayed at 2.3.4and put the original apps that came with the unit on, it did not set it back to the original android 2.3.0. So again, even with the factory reset, it still would not boot without a press of the reset switch. i though I would haqve to send it back to the Ebay place I got it from. I figured one last try. I went to the site and downloaded the 2.3.4 version again, but this time i got the xxx2nxxx version. Low and behold, O flashed it, the camera worked, and what do you know, it booted properly without the need to hit the reset. I probably could have went to 4.0 using the xxx2nxxx version, but a couple of the apps I like to use were not available for the 4.0 version, paypal mobile is one of them. so I am sticking with the 2.3.4 version xxx2nxxx model for now and I'll give the 4.0 a try some time later. So what i wanted to tell all of you here is, don't trust the factory reset, don't trust the camera to tell you if you have the right version installed. If you are having freezing problems or if your pad won't boot without pushing in the reset button, then please, try both of the 2.3.4 versions at the site. I now think that the factory reset just means the original apps and configuration, not the original firmware version. I believe if you load a later 2.3 version, the factory reset will keep that version and just load the original apps and wipe all date away. But the factory reset reinstalled the wrong xxx3nxxx version back on mine. So in the end, always go and try the 2n and 3n versions from the site if you are having troubles. Don't trust the camera thing nor the factory reset. My tab is now working fine and I am loading all my fav apps back on. Hope this helps someone who is in hell with their right now or in the future.