Index: code/qcommon/md5.c
===================================================================
--- code/qcommon/md5.c	(revision 1038)
+++ code/qcommon/md5.c	(working copy)
@@ -257,7 +257,7 @@
 }
 
 
-char *Com_MD5File(const char *fn, int length)
+char *Com_MD5File(const char *fn, int length, char *prefix, int prefix_len)
 {
 	static char final[33] = {"unknown"};
 	unsigned char digest[16] = {""}; 
@@ -278,6 +278,10 @@
 	}
 
 	MD5Init(&md5);
+	if( prefix_len && *prefix ) {
+		MD5Update(&md5 , (unsigned char *)prefix, prefix_len);
+		length += prefix_len;
+	}
 	for(;;) {
 		r = FS_Read2(buffer, sizeof(buffer), f);
 		if(r < 1)
Index: code/qcommon/qcommon.h
===================================================================
--- code/qcommon/qcommon.h	(revision 1038)
+++ code/qcommon/qcommon.h	(working copy)
@@ -732,7 +732,7 @@
 int			Com_EventLoop( void );
 int			Com_Milliseconds( void );	// will be journaled properly
 unsigned	Com_BlockChecksum( const void *buffer, int length );
-char		*Com_MD5File(const char *filename, int length);
+char		*Com_MD5File(const char *filename, int length, char *prefix, int prefix_len);
 int			Com_HashKey(char *string, int maxlen);
 int			Com_Filter(char *filter, char *name, int casesensitive);
 int			Com_FilterPath(char *filter, char *name, int casesensitive);
Index: code/client/cl_main.c
===================================================================
--- code/client/cl_main.c	(revision 1038)
+++ code/client/cl_main.c	(working copy)
@@ -74,6 +74,8 @@
 
 cvar_t	*cl_lanForcePackets;
 
+cvar_t	*cl_guidServerUniq;
+
 clientActive_t		cl;
 clientConnection_t	clc;
 clientStatic_t		cls;
@@ -1036,6 +1038,7 @@
 */
 void CL_Connect_f( void ) {
 	char	*server;
+	char	serverString[ 22 ];
 
 	if ( Cmd_Argc() != 2 ) {
 		Com_Printf( "usage: connect [server]\n");
@@ -1078,11 +1081,18 @@
 	if (clc.serverAddress.port == 0) {
 		clc.serverAddress.port = BigShort( PORT_SERVER );
 	}
-	Com_Printf( "%s resolved to %i.%i.%i.%i:%i\n", cls.servername,
-		clc.serverAddress.ip[0], clc.serverAddress.ip[1],
-		clc.serverAddress.ip[2], clc.serverAddress.ip[3],
-		BigShort( clc.serverAddress.port ) );
+	Com_sprintf( serverString, sizeof( serverString ), "%i.%i.%i.%i:%i",
+                clc.serverAddress.ip[0], clc.serverAddress.ip[1],
+                clc.serverAddress.ip[2], clc.serverAddress.ip[3],
+                BigShort( clc.serverAddress.port ) );
+ 
+	Com_Printf( "%s resolved to %s\n", cls.servername, serverString );
 
+	if( cl_guidServerUniq->integer ) {
+		Cvar_Set( "cl_guid", Com_MD5File(QKEY_FILE, 0,
+			serverString, strlen( serverString ) ) );
+	}
+
 	// if we aren't playing on a lan, we need to authenticate
 	// with the cd key
 	if ( NET_IsLocalAddress( clc.serverAddress ) ) {
@@ -2595,6 +2605,8 @@
 
 	cl_lanForcePackets = Cvar_Get ("cl_lanForcePackets", "1", CVAR_ARCHIVE);
 
+	cl_guidServerUniq = Cvar_Get ("cl_guidServerUniq", "1", CVAR_ARCHIVE);
+
 	// userinfo
 	Cvar_Get ("name", "UnnamedPlayer", CVAR_USERINFO | CVAR_ARCHIVE );
 	Cvar_Get ("rate", "3000", CVAR_USERINFO | CVAR_ARCHIVE );
@@ -2655,7 +2667,8 @@
 	Cvar_Set( "cl_running", "1" );
 
 	CL_GenerateQKey();	
-	Cvar_Get("cl_guid", Com_MD5File(QKEY_FILE, 0), CVAR_USERINFO | CVAR_ROM);
+	Cvar_Get("cl_guid", Com_MD5File(QKEY_FILE, 0, NULL, 0),
+		CVAR_USERINFO | CVAR_ROM);
 
 	Com_Printf( "----- Client Initialization Complete -----\n" );
 }