Weird... I expected little size variations in the working data. Code size should be neglectable when compared to it. The only data that is affected is pointers and, unless you have a lot of pointers and a little data being pointed to, the difference should not be measurable.
Of course, the programmer could be using register-size integers for all the data.
http://journal.dedasys.com/2008/11/24/slicehost-vs-linode