How much do I weigh?

This morning I get up and changed the batteries in my scale. It had been pitifully giving me the Lo Bat warning for far too long. I stepped on and assumed the position of prayer to God that the numbers would be lower.
They weren't. 318.9
I said some ugly words and stepped on again, 319.00, again 320.00.Uhhh was I gaining weight at the speed of smell!? What the hell was going on here? I look over at the other older scale and raise my eyebrow. Let me back up a bit here. Since I started my weight loss back in October of 2008 I was 350 pounds it would not weigh me because it's cap out was 330.Now that I am happily below 330 I thought to myself, let's give the old one a go and see what it has to contribute.
309 says old scale. I think it was trying to get back in my good graces.I weigh one, two, three more times on old scale 309 each time. I like the old scale, but I know he is lying to me...I think.

Now that I am completely perplexed I get back on the other scale and it says 318.So who or what do I believe? How do I know how much I weigh?I have been on a plateau for two weeks and now I have dueling scales...ugh.
I trudge on forward through my weight loss battle clueless as to my true weight. I suppose the only thing that matters is that my clothes are getting looser and I feel much better. I will weigh again tomorrow and see how much each one thinks I weigh.