diff -urp linux-2.6.21.orig/drivers/video/pm2fb.c linux-2.6.21.old/drivers/video/pm2fb.c
--- linux-2.6.21.orig/drivers/video/pm2fb.c	2007-04-26 22:59:21.697777668 +0200
+++ linux-2.6.21.old/drivers/video/pm2fb.c	2007-04-22 19:42:29.715214265 +0200
@@ -1139,10 +1144,10 @@ static int __devinit pm2fb_probe(struct 
 		default_par->mem_control, default_par->boot_address,
 		default_par->mem_config);
 
-	default_par->memclock = CVPPC_MEMCLOCK;
 	if(default_par->mem_control == 0 &&
 		default_par->boot_address == 0x31 &&
 		default_par->mem_config == 0x259fffff) {
+		default_par->memclock = CVPPC_MEMCLOCK;
 		default_par->mem_control=0;
 		default_par->boot_address=0x20;
 		default_par->mem_config=0xe6002021;
@@ -1162,7 +1167,7 @@ static int __devinit pm2fb_probe(struct 
 			DPRINTK("We have not been initialized by VGA BIOS "
 				"and are running on an 3dlabs reference board\n");
 			DPRINTK("Initializing card timings manually...\n");
-			default_par->memclock=70000;
+			default_par->memclock=74894;
 		}
 	}