This might have to do with some browser security features in Firefox that block access to local files, that aren't present in chrome/IE. It might require using a proxy to make it look like it's from somewhere else, or a workaround to the local restriction. A few links below that might explain a bit better.

Blog post from a GIS developer who had a kml issue somewhat similar: http://reganbj.blogspot.ca/2009/10/mystery-solved.html

Summary of issue from Mozillazine, summarizing the basis for the problem: http://kb.mozillazine.org/Links_to_local_pages_do_not_work

Stack overflow questions relating to the issue (many other related Q's on overflow and superuser): http://stackoverflow.com/questions/192080/firefox-links-to-local-or-network-pages-do-not-work?rq=1 http://stackoverflow.com/questions/7331997/kml-layer-in-openlayers-doesnt-work-on-localhost?rq=1

This might have to do with some browser security features in Firefox that block access to local files, that aren't present in chrome/IE. It might require using a proxy to make it look like it's from somewhere else, or a workaround to the local restriction. A few links below that might explain a bit better.

Blog post from a GIS developer who had a kml issue somewhat similar: http://reganbj.blogspot.ca/2009/10/mystery-solved.html

Summary of issue from Mozillazine, summarizing the basis for the problem: http://kb.mozillazine.org/Links_to_local_pages_do_not_work

Stack overflow questions relating to the issue (many other related Q's on overflow and superuser): https://stackoverflow.com/questions/192080/firefox-links-to-local-or-network-pages-do-not-work?rq=1 https://stackoverflow.com/questions/7331997/kml-layer-in-openlayers-doesnt-work-on-localhost?rq=1