Some additional feedback: SetPageSize() is apparently ignored if there are any paragraphs on ANY page in the document, not just on the one whose size is being changed. Here is some code that reproduces the issue, with comments regarding the results for of each page.
//ISSUE: SetPageSize() doesn’t work if paragraphs are added to ANY page
//in the document
//Note: using Page.PageInfo.Height/Width works OK)
var doc = new Document();
Page page;
//SUCCESS: Setting Width/Height dimensions works,
page = doc.Pages.Add();
page.Paragraphs.Add(new TextFragment(“page 1”));
page.PageInfo.Height = 200;
page.PageInfo.Width = 600;
//FAIL: SetPageSize() is ignored because there are paragraphs
page = doc.Pages.Add();
page.Paragraphs.Add(new TextFragment(“page 2”));
page.SetPageSize(600, 200); //this is ignored
//FAIL: SetPageSize() is ignored because there are paragraphs
page = doc.Pages.Add();
var box = new FloatingBox(200, 100);
box.Paragraphs.Add(new TextFragment(“page 3”));
page.Paragraphs.Add(box);
page.SetPageSize(600, 200);
//FAIL: SetPageSize() is ignored, even with no paragraphs on the page,
// apparently because there are paragraphs on OTHER pages
// comment out the creation of pages 1 - 3
page = doc.Pages.Add();
page.SetPageSize(600, 200);
//save and done
doc.Save(“c:\test2.pdf”);
Process.Start(“c:\test2.pdf”);