At first, with default settings, Firefox would not open pdf files & came up only with a blank screen & no file reference. Going to options/applications & changing the default to a new installation of Adobe Reader still brought up a blank screen but this time with the file ref. Oddly though, attempting to open any pdf file would then change the setting under applications back to Use Adobe Acrobat (in Firefox). But this doesn't work. So what do I need to do to get Firefox to open pdf files correctly using Adobe Reader?