1.) Change the mouse sensitivity settings within your operating system. This has the downside of increasing the sensitivity globally- which you probably don't want. That said it should certainly solve the problem.
2.) Some mice come with software where you can create profiles for individual games. I know Logitech & Razor have programs like this. You can use these programs to remap the mouse buttons differently for each game. Whether or not you can set a sensitivity for each game I don't know but that would probably be a better solution. There might also be a generic program that could do this- in which case I would recommend Google.
- Ryan Paul Fialcowitz