...as reported by Simon in the forum, and the reason is that it believes it is sent non-gzip-encoded SVG files. If we change the file suffixes to .svgz and add this to the .htaccess in the svg directory, both Firefox and the other SVG viewers I have tried seems happy: AddType image/svg+xml .svgz AddEncoding gzip .svgz <FilesMatch \.svgz$> <IfModule mod_gzip.c> mod_gzip_on No </IfModule> </FilesMatch> (But I have no write access, and yes, this requires changing the EC.) -- Thomas