--- /usr/portage/www-client/firefox/firefox-5.0-r2.ebuild	2011-07-06 07:14:18.000000000 +0200
+++ firefox-5.0-r2.ebuild	2011-07-06 12:13:48.383758219 +0200
@@ -244,10 +244,10 @@
 
 	if [[ $(gcc-major-version) -lt 4 ]]; then
 		append-cxxflags -fno-stack-protector
-	fi
-
-	if use amd64 || use x86; then
-		append-flags -mno-avx
+	elif [[ $(gcc-major-version) -gt 4 || $(gcc-minor-version) -gt 3 ]]; then
+		if use amd64 || use x86; then
+			append-flags -mno-avx
+		fi
 	fi
 }