I'm not able to get Steam to recognize any of my achievements. Also, it always says that I have played for over 1 minute, despite having a few hours logged in already. This is on Mac OS 10.9.1 and the latest version of Steam.
For this issue you'd be best off contacting actual Steam support as it isn't a problem with the game itself, but rather the Steam connection to it. I know everything is working nicely in general, so it may just be some oddity that's come up with your specific account.