diff --git a/code/renderer/tr_init.c b/code/renderer/tr_init.c
index c27afecd..57c4a24b 100644
--- a/code/renderer/tr_init.c
+++ b/code/renderer/tr_init.c
@@ -143,6 +143,8 @@ cvar_t	*r_debugSort;
 cvar_t	*r_printShaders;
 cvar_t	*r_saveFontData;
 
+cvar_t	*r_GLlibCoolDownMsec;
+
 cvar_t	*r_maxpolys;
 int		max_polys;
 cvar_t	*r_maxpolyverts;
@@ -988,6 +990,8 @@ void R_Register( void )
 	r_maxpolys = ri.Cvar_Get( "r_maxpolys", va("%d", MAX_POLYS), 0);
 	r_maxpolyverts = ri.Cvar_Get( "r_maxpolyverts", va("%d", MAX_POLYVERTS), 0);
 
+	r_GLlibCoolDownMsec = ri.Cvar_Get( "r_GLlibCoolDownMsec", "0", CVAR_ARCHIVE );
+  
 	// make sure all the commands added here are also
 	// removed in R_Shutdown
 	ri.Cmd_AddCommand( "imagelist", R_ImageList_f );
diff --git a/code/renderer/tr_local.h b/code/renderer/tr_local.h
index e29feba6..e9de83ad 100644
--- a/code/renderer/tr_local.h
+++ b/code/renderer/tr_local.h
@@ -1091,6 +1091,8 @@ extern	cvar_t	*r_debugSort;
 extern	cvar_t	*r_printShaders;
 extern	cvar_t	*r_saveFontData;
 
+extern	cvar_t	*r_GLlibCoolDownMsec;
+
 //====================================================================
 
 float R_NoiseGet4f( float x, float y, float z, float t );
diff --git a/code/unix/linux_qgl.c b/code/unix/linux_qgl.c
index b38edbcb..d4841c27 100644
--- a/code/unix/linux_qgl.c
+++ b/code/unix/linux_qgl.c
@@ -2651,6 +2651,24 @@ void QGL_Shutdown( void )
 {
 	if ( glw_state.OpenGLLib )
 	{
+		// 25/09/05 Tim Angus <tim@ngus.net>
+		// Certain combinations of hardware and software, specifically
+		// Linux/SMP/Nvidia/agpgart (OK, OK. MY combination of hardware and
+		// software), seem to cause a catastrophic (hard reboot required) crash
+		// when libGL is dynamically unloaded. I'm unsure of the precise cause,
+		// suffice to say I don't see anything in the Q3 code that could cause it.
+		// I suspect it's an Nvidia driver bug, but without the source or means to
+		// debug I obviously can't prove (or disprove) this. Interestingly (though
+		// perhaps not suprisingly), Enemy Territory and Doom 3 both exhibit the
+		// same problem.
+		//
+		// After many, many reboots and prodding here and there, it seems that a
+		// placing a short delay before libGL is unloaded works around the problem.
+		// This delay is changable via the r_GLlibCoolDownMsec cvar (nice name
+		// huh?), and it defaults to 0. For me, 500 seems to work.
+		if( r_GLlibCoolDownMsec->integer )
+			usleep( r_GLlibCoolDownMsec->integer * 1000 );
+
 		dlclose ( glw_state.OpenGLLib );
 		glw_state.OpenGLLib = NULL;
 	}