Anything tagged with <pre> appears in the pdf in Times font.

We tried these definitions in the css for pre

pre {
 font-family : courier;
}

and

pre {
 font-family : "Courier-new";
}

Neither worked.

However,

pre {
 font-family : "Courier-new" !important; 
}

worked.

The default XHTML style sheet maps <pre> to "monospace", and Prince maps monospace to Courier New, Courier, or DejaVu Sans Mono, in that order. Most systems have Courier New installed, but I haven't seen it require a hyphen before. What operating system and version are you running?