--- xorg-server-1.2.99.901/hw/xfree86/os-support/bus/linuxPci.c~	2006-11-16 18:01:25.000000000 +0000
+++ xorg-server-1.2.99.901/hw/xfree86/os-support/bus/linuxPci.c	2007-03-07 15:44:10.000000000 +0000
@@ -158,7 +158,13 @@ linuxPciOpenFile(PCITAG tag, Bool write)
 		if (stat("/sys/bus/pci",&ignored) < 0)
 			is26 = 0;
 		else
-			is26 = 1;
+			/* If we don't find the incompatible IA64 "domain support" in
+			   /proc/bus/pci then we don't know domain numbers. This means
+			   we ought to use /proc/bus/pci for accessing devices, instead
+			   of /sys/bus/pci. So in that case we just pretend it's a 2.4
+			   kernel, and hope the kernel has set up disjoint bus numbers
+			   for us, like it always used to. */
+			is26 = domain_support;
 	}
 	
 	if (!domain_support && domain > 0)