Index: Slim/Player/Squeezebox.pm
===================================================================
--- Slim/Player/Squeezebox.pm	(revision 23728)
+++ Slim/Player/Squeezebox.pm	(working copy)
@@ -216,7 +216,9 @@
 }
 
 sub signalStrength {
-	return Slim::Networking::Slimproto::signalStrength(@_);
+	my $sig = Slim::Networking::Slimproto::signalStrength(@_);
+	
+	return $sig ? $sig."%" : undef;
 }
 
 sub hasIR() { 
Index: Slim/Menu/SystemInfo.pm
===================================================================
--- Slim/Menu/SystemInfo.pm	(revision 23728)
+++ Slim/Menu/SystemInfo.pm	(working copy)
@@ -168,7 +168,7 @@
 		{ INFORMATION_PLAYER_IP              => $client->ip },
 #		{ INFORMATION_PLAYER_PORT            => $client->port },
 		{ INFORMATION_PLAYER_MAC             => $client->macaddress },
-		{ INFORMATION_PLAYER_SIGNAL_STRENGTH => $client->signalStrength . '%' },
+		{ INFORMATION_PLAYER_SIGNAL_STRENGTH => $client->signalStrength},
 		{ INFORMATION_PLAYER_VOLTAGE         => $client->voltage },
 	];