diff -uNr os-prober.orig/os-probes/init/common/10filesystems os-prober/os-probes/init/common/10filesystems
--- os-prober.orig/os-probes/init/common/10filesystems	2011-05-14 18:09:08.000000000 +0200
+++ os-prober/os-probes/init/common/10filesystems	2011-07-28 22:42:38.435323475 +0200
@@ -26,7 +26,9 @@
 			fs-*)
 				;;
 			*)
-				modprobe "$fs" 2>/dev/null | logger -t os-prober
+				if ! grep -q "\s$fs" /proc/filesystems; then
+					modprobe "$fs" 2>/dev/null | logger -t os-prober
+				fi
 				;;
 		esac
 	done