yeast starter. I'm getting multiple numbers

Alright, essentially trying to ferment 7 gallons of 1.080 wort style set to (21b)black IPA.
According to the starter tab in my recipe design I need 514.2 bil. cells.
I go to the yeast starter in tools sections input Ale or Cider, 7 gals, OG 1.080. comes up with 384.2bil.

at this point i'm thinkin that's kind of a difference guess i'll have to do it by hand. Use the recommended pitching rate I found on a beersmith blog about making yeast starters of 0.71billions cells per gallon times SG. end up with 397.6 billion cells. reasonably close.

Any ideas why my recipe design calls for so many more cells?

IIRC, the stand alone starter tool uses the current date for the purpose of figuring viability. If you enter the current date in your recipe the results should be the same. Also make sure the yeast dates are the same.

Thus the old adage that a man with a thermometer knows exactly what the temperature is.  A man with two thermometers is always in doubt.

As BOB357 noted, you need to make sure that the packaging date on your yeast is set correctly in the recipe.  Beyond that, if you are not doing cell counts then it really doesn't matter which recommendation you go by.  Yeast starter calculations are meant to get you in the ball park of reasonable cell counts.  Just like every brewer's process is different, everyone's starter procedure is a little different and can lead to variable results from the starter being made.  Further to that, cell counts in a yeast pack are approximate.  Check on the web sites for Wyeast and White Labs and they will list the range of viable cells which are usually contained within a package. 

Between the two calculators within BeerSmith, if I were to compare them I would certainly trust the one within the recipe as it has access to better information than what the stand alone calculator is fed.  Realize also, that these numbers are based upon calculated numbers already, so that will just compound any deviation from ideal cell counts.  In the end, what is important is having a healthy, viable cell population which can readily reproduce sufficiently in the wort it is pitched without growing too strained or weak.