quick question about the herpstat--the new ones measure temps to a tenth of a degree. my question is, when did this feature become available? i bought 2 used herpstats that are fairly new but they don't seem to measure the tenth of a degree--just single degrees--97 as opposed to 97.5. there isn't any setting that you have to enable to turn on the tenth of a degree is there? i just want to make sure i just have the older model and that i'm not missing out.