Changing equipment profile changes recipes amounts

I switch between 12 gallon batches at home and 7 barrel batches at work, but frequently when i change the profiles and the units in the "tools" - "options" section, it will mess up my recipes.

For instance it will change 250lbs of base malt to 248lbs, 8 ounces. Also, sometimes it seems to automatically scale the recipes to one equipment profile or the other without me asking it to do it. And when I try to scale it back to the right profile, and size, the units get all messed. Don't know what is going on, but it is pretty annoying.

Hi,
  Unfortunately what is happening is rounding of the figures.  BeerSmith "auto calculates" items so when you change any value it will change other values related to that.  A consequence of that is it takes the "rounded" value in a field and applies it.

  So when you go from english to metric, the values are computed in metric and rounded to the precision of your display units.  When you convert back to english, that rounding causes some errors.

  You can mitigate this slightly by increasing the precision for many unit values (from the units tab of the options dialog).

Brad