diff -Naur sylpheed-2.4.1.orig/libsylph/defs.h sylpheed-2.4.1/libsylph/defs.h
--- sylpheed-2.4.1.orig/libsylph/defs.h	2006-09-22 11:58:56.000000000 +0900
+++ sylpheed-2.4.1/libsylph/defs.h	2007-05-07 17:25:18.000000000 +0900
@@ -92,7 +92,7 @@
 /* #define DEFAULT_INC_PATH	"/usr/bin/imget" */
 /* #define DEFAULT_INC_PROGRAM	"imget" */
 #define DEFAULT_SENDMAIL_CMD	"/usr/sbin/sendmail -t -i"
-#define DEFAULT_BROWSER_CMD	"mozilla-firefox -remote 'openURL(%s,new-window)'"
+#define DEFAULT_BROWSER_CMD	"firefox -remote 'openURL(%s,new-window)'"
 
 #ifdef _PATH_MAILDIR
 #  define DEFAULT_SPOOL_PATH	_PATH_MAILDIR