diff --git a/drivers/video/matrox/g450_pll.c b/drivers/video/matrox/g450_pll.c
index 09f6e045d5beb19755a3449c711cf746321d9c4e..c15f8a57498ed15e9538c18f78c5ced10c42144e 100644
--- a/drivers/video/matrox/g450_pll.c
+++ b/drivers/video/matrox/g450_pll.c
@@ -368,7 +368,8 @@ static int __g450_setclk(struct matrox_fb_info *minfo, unsigned int fout,
 					M1064_XDVICLKCTRL_C1DVICLKEN |
 					M1064_XDVICLKCTRL_DVILOOPCTL |
 					M1064_XDVICLKCTRL_P1LOOPBWDTCTL;
-				matroxfb_DAC_out(minfo, M1064_XDVICLKCTRL, tmp);
+                                /* Setting this breaks PC systems so don't do it */
+				/* matroxfb_DAC_out(minfo, M1064_XDVICLKCTRL, tmp); */
 				matroxfb_DAC_out(minfo, M1064_XPWRCTRL,
 						 xpwrctrl);