My weight for the past week is no where near what my bodybugg says it should be, and I have no idea why. In the past, I've found bb extremely accurate. Here's the deal:

August 5: 255 pounds (bodybugg accurate)
Today (8/13): 257 pounds but body bugg says I should be 250.5 by now. That's a 6.5 pound difference than what I'm experiencing.

Reasons why I don't understand where the inaccuracies are coming from:

-I have normal thyroid function (was tested in the last four months)
- I am extremely meticulous about counting calories in (using both scale and measuring cups and checking each ingredient with several databases)
-I have not started a new physical fitness regime, and am not retaining water.
-I am not eating excess salt, and am not retaining water.
-This is not a normal time in my hormonal cycle for water retention and am not retaining water (my body has been consistent on water retention cycles for years).
-I bought a new, more accurate scale to double check. My scale is not inaccurate.
-I have no reason to believe I could be gaining muscle (only current exercise walking)

Anyone have a brilliant idea about this? I know a lot of people will want to respond saying you can't trust bodybugg or other calories-out devices, but honestly, I've used one for 5 months and have never had inaccuracies.