Alright, so there has been a recent problem on Xbox Live where peoples gamerscore has jumped randomly due to Gears of War 3. But it has also been happening to people without Gears. Such as me. Went from 3365 to 25010. One way to fix it was to recover your account, and then when you got another achievement, your gamerscore would jump again. Well on the Xbox Forums, they claimed that they're looking into it. So it should be fixed soon. Just felt like I had to let you guys know.