diff --git a/src/add-ons/accelerants/nvidia/engine/nv_agp.c b/src/add-ons/accelerants/nvidia/engine/nv_agp.c
index 0cdedb26e9..e62831d684 100644
--- a/src/add-ons/accelerants/nvidia/engine/nv_agp.c
+++ b/src/add-ons/accelerants/nvidia/engine/nv_agp.c
@@ -1,5 +1,5 @@
 /* Author:
-   Rudolf Cornelissen 6/2004-5/2005
+   Rudolf Cornelissen 6/2004-4/2006
 */
 
 #define MODULE_BIT 0x00000100
@@ -10,7 +10,7 @@
 static void nv_agp_list_info(agp_info ai);
 static void nv_agp_list_active(uint32 cmd);
 
-status_t nv_agp_setup(void)
+status_t nv_agp_setup(bool enable_agp)
 {
 	nv_nth_agp_info nai;
 	nv_cmd_agp nca;
@@ -105,10 +105,13 @@ status_t nv_agp_setup(void)
 		return B_ERROR;
 	}
 
-	if (si->settings.force_pci)
+	if (si->settings.force_pci || !enable_agp)
 	{
 		/* set PCI mode if specified by user in nv.settings */
-		LOG(4,("AGP: forcing PCI mode (specified in nv.settings)\n"));
+		if (enable_agp)
+			LOG(4,("AGP: forcing PCI mode (specified in nv.settings)\n"));
+		else
+			LOG(4,("AGP: forcing PCI mode during coldstart (required)\n"));
 
 		/* let the AGP busmanager setup PCI mode.
 		 * (the AGP speed scheme is of no consequence now) */
diff --git a/src/add-ons/accelerants/nvidia/engine/nv_general.c b/src/add-ons/accelerants/nvidia/engine/nv_general.c
index fe76b4cf16..66d398dd0e 100644
--- a/src/add-ons/accelerants/nvidia/engine/nv_general.c
+++ b/src/add-ons/accelerants/nvidia/engine/nv_general.c
@@ -91,7 +91,7 @@ status_t nv_general_powerup()
 {
 	status_t status;
 
-	LOG(1,("POWERUP: Haiku nVidia Accelerant 0.79 running.\n"));
+	LOG(1,("POWERUP: Haiku nVidia Accelerant 0.80 running.\n"));
 
 	/* log VBLANK INT usability status */
 	if (si->ps.int_assigned)
@@ -1392,6 +1392,15 @@ static status_t nvxx_general_powerup()
 	 * at system power-up POST time. */
 	if (!si->settings.usebios)
 	{
+		/* Make sure we are running in PCI (not AGP) mode:
+		 * This is a requirement for safely coldstarting cards!
+		 * (some cards reset their AGP PLL during startup which makes acceleration
+		 *  engine DMA fail later on. A reboot is needed to overcome that.)
+		 * Note:
+		 * This may only be done when no transfers are in progress on the bus, so now
+		 * is probably a good time.. */
+		nv_agp_setup(false);
+
 		LOG(2, ("INIT: Attempting card coldstart!\n"));
 		/* update the cardspecs in the shared_info PINS struct according to reported
 		 * specs as much as is possible;
@@ -1681,7 +1690,7 @@ static status_t nv_general_bios_to_powergraphics()
 	 * Note:
 	 * This may only be done when no transfers are in progress on the bus, so now
 	 * is probably a good time.. */
-	nv_agp_setup();
+	nv_agp_setup(true);
 
 	return B_OK;
 }
diff --git a/src/add-ons/accelerants/nvidia/engine/nv_proto.h b/src/add-ons/accelerants/nvidia/engine/nv_proto.h
index 091ccf0075..42dc7a9d9e 100644
--- a/src/add-ons/accelerants/nvidia/engine/nv_proto.h
+++ b/src/add-ons/accelerants/nvidia/engine/nv_proto.h
@@ -8,7 +8,7 @@ status_t nv_general_head_select(bool);
 status_t nv_general_validate_pic_size (display_mode *target, uint32 *bytes_per_row, bool *acc_mode);
 
 /* AGP functions */
-status_t nv_agp_setup(void);
+status_t nv_agp_setup(bool enable_agp);
 
 /* apsed: logging macros */
 #define MSG(args) do { /* if needed or si->settings with si NULL */ \