There is no FontResolver with version 1.32.
Make sure the required fonts are installed on the web server and also make sure your application has sufficient privileges to access those fonts.
When PDFsharp tries to access a font that is not available, the system will return MS Sans Serif without an error message and PDFsharp does not even know it got the wrong font and the PDF file shows the wrong font name.
Alternative: use the WPF build of PDFsharp 1.32, add the fonts to your application and add them to the XPrivateFontCollection.
There is a working sample in the source code package.
See also:
http://pdfsharp.net/wiki/PrivateFonts-sample.ashxOr use PDFsharp 1.50 beta (WPF) with a FontResolver.