1.7.1 Security Settings and Firefox

I’ve just upgraded to v.1.7.1 and am having a problem with PDFs that are opened in Firefox.  I have encryption set to 128 bit, disallow user to copy text and images and modify document.  They are allowed to print.  These settings are respected if the PDF is opened in Adobe Reader and Chrome, but if it’s opened in Firefox, copying of the text is allowed.  I haven’t checked IE.