I have installed the latest hddtemp 0.3-beta15.52 and lm-sensors 1:3.3.3 everything was fine in 13.04 Raring, but after upgrade hdd temp isn't showing. I'm using Hardware sensors indicator. I've tried with psensors but the same thing here.
edit:
Yesterday, noticed that hddtemp tool in the terminal shows my hdd temp correct. Maybe hardware system indicator doesn't pull correct this temp and needs to be updated for Saucy.