This looks like the tag is not associated.
The battery voltage "3.18" is what was returned by the tag as response to the "Search new tag" button.
No temperature is returned, which is only returned as response to the update command.
First, click Settings->Undelete a tag, to make sure all tags are showing up. Click update or light on command on each one to see if any can control the tag.
If none can control it, the tag is still not associated. The LED should be flashing. If not flashing, please open the case and short hole #3 with #1 to reset the flash memory (
http://store.wirelesstag.net/pages/support#factory_reset) Once the LED is flashing you can search & associate it again.