With the last few releases, I could no longer use the fn key on my powerbook as a fake mouse modifier. Here is patch to darwinEvents.c, based on an earlier commit "Re- enable support for capslock", that allows fn to be used again for fake_button2 or 3: --- xorg-server-1.4.2-apple41/hw/xquartz/darwinEvents.c.orig 2009-04-11 11:01:07.000000000 -0400 +++ xorg-server-1.4.2-apple41/hw/xquartz/darwinEvents.c 2009-04-11 11:17:20.000000000 -0400 @@ -155,7 +155,7 @@ int darwin_modifier_mask_list[] = { #else NX_CONTROLMASK, NX_SHIFTMASK, NX_COMMANDMASK, NX_ALTERNATEMASK, #endif - NX_ALPHASHIFTMASK, + NX_ALPHASHIFTMASK, NX_SECONDARYFNMASK, 0 }; @@ -175,7 +175,7 @@ static void DarwinUpdateModifiers( } for(f=darwin_modifier_mask_list; *f; f++) - if(*f & flags && *f != NX_ALPHASHIFTMASK) { + if(*f & flags && *f != NX_ALPHASHIFTMASK && *f != NX_SECONDARYFNMASK) { key = DarwinModifierNXMaskToNXKey(*f); if(key == -1) ErrorF("DarwinUpdateModifiers: Unsupported NXMask: 0x%x\n", *f); I prefer to use the fn key for one of the fake clicks because some X apps have a use for shift, control, or option clicks. Thanks, Martin