Comment 6 for bug 615591

Okay I think your initial comment of a race condition is correct - what probably happens is sensors-applet starts up before hddtemp so it initially fails to find the sensor, and hence the hddtemp plugin is unloaded. Because of this even once the saved sensor data is loaded after intial startup, we fail to be able to get the temperature since we already unloaded the plugin. This has been fixed upstream - if you're able to compile from the upstream git repo you could test that to ensure the bug is fixed, otherwise when the next version is released it should contain the fix.