If I want to select an option of a dropdown box, there are several ways to do that. I always used:
driver.findElem
For some strange reason the SelectElement for webdriver (version 2.25.1.0) does not properly work with the firefoxdriver (Firefox 15). Sometimes it may not select an option from a dropdownlist. It does, however, seem to work with the chromedriver... This is a link to the chromedriver... just drop it in the bin dir.