I am looking for help with my partners SE Xperia X10 smartphone which appears to have developed an issue with what I originally thought was the battery in the phone, as it can be on charge all evening and dis-charge within a day, despite me disabling the wi-fi functions etc. I purchased a new battery for the phone and went about swapping them over. Despite charging for 8 hours as instructed with a new battery the phone would not switch on with the new battery installed, so I put the old battery back in. Now whilst swapping the batteries over the smartphone appears to have gone crazy, it lost the current date and time, any messages that were sent during that time showed in the homescreen but couldn't be found in the inbox itself, however all the phone contacts, apps and messages sent earlier were all accessible, which leads me to think that this means that something else is up with this phone. Can anybody offer some advice please? Thanks in advance.