My scale is posessed!

So, scale problems. I am trying to decide what to do. The one I have been using all this time is driving me nuts. It takes about 20 tries to get two readings that match, half of those tries results in Errors! I have tried different spots on the bathroom floor, cleaning the floor, it doesn't seem to matter. And the biggest head scratcher? I of course tried replacing the batteries. I tried fully-charged rechargeables first. The scale wouldn't even turn on! Then I tried new regular batteries. Same thing, it wouldn't turn on. I put the old cheapo generic batteries back in there and it turned back on. I have had that scale for 3 years and those are the same batteries since the first day. It won't accept any other batteries. It's a home edics one from Wal-Mart that I paid about $30 for. I am thinking about using another digital scale that my oldest son uses, but it always measured about 2 pounds heavier than mine, but at least his one gives you the same number no problem twice in a row. What have you guys done, and can you suggest a better scale that is not insanely priced? Thanks!

Actually, it's a health-o-meter one from Wally World. Just checked.