recipe disagreements

[Radler]

I was wondering if anybody can tell me why I get such different results on recipes when using two different "methods". When I calculate what the OG and IBU etc will be using tastybrew.com it comes out very differently than if I use calculations from John Palmer's "How to Brew". I trust both of these but they can't be so different and both right. Example is my last beer: 5.75 lbs of extract gave me a 1.046 OG with Palmer and a 1.055 on tastybrew, when I actually brewed it and neasured it, tasty brew was right, but Palner doesn't have a book by being wrong. Any ideas folks?

Rad

 

[Walker]

did you have any specialty grains in there that you forgot to take into consideration when using palmer's method?

1.055 with 5.75lbs of extract is way too high, unless your extract provides a LOT of points per pound per gallon.