I use Excel 2010 with VBA.
I have the following code :
mySh.PageSetup.PaperSize = xlPaperLetter
mySh.ExportAsFixedFormat Type:=xlTypePDF, _
Filen
I also use Excel 2010 and had the same problem. When using ExportAsFixedFormat, the page won't scale. From what I understand, it is the same as using the Save As with file type pdf. This means that you need to need to scale your workbook to fit the page that you require.
If you:
-Open printer settings and select 'No Scaling'
-Page Layout > Print Area > Clear Print Area
-Select View > Page Break View
It will show you the page area. If you scale your worksheet to this it will save to pdf using ExportAsFixedFormat properly.