If you're trying to control CPU and GPU fans only than simply remove SpeedFan. Bios can control CPU fan perfectly, and ATI tray tools or something simillar will do for GPU. As far as SpeedFan i've been trying to control chasis fans and it's impossible. So i have installed front panel with fan support and that does it.
As is said, in my case the cpu fan control worked really well with the curve i set up.
A lot better than with the BIOS control where it was randomly spinning up and down.
I just dont get why it just stopped working