If you follow the link on that page to the developer's site you find that some users have an issue with the program running under 64 bit SL. Then again the page is dated 2009 or so - has there been any update since then? Anybody running smcfancontrol in 64 bit mode & SL? 10.6.6 on a Mac mini here. Lastly - I thought smc was a paid program or is it free now?