Just google it. It's definitely not a software problem because some people never experienced it. Basically the screen becomes unusable as if you were pressing c

Just google it. It's definitely not a software problem because some people never experienced it. Basically the screen becomes unusable as if you were pressing constantly its bottom part. Given that the nexus one doesn't really have a real multitouch, your input will be averaged with a pressure on the bottom and the cursor will always move somewhere in between the spot you touched and the lower edge of the screen. For some reason, you lock the phone by pressing the power button, you unlock it and it's fine again. It happens to me maybe once or twice a week.