diff -up pciutils-3.0.0/lib/access.c.scan pciutils-3.0.0/lib/access.c
--- pciutils-3.0.0/lib/access.c.scan	2008-04-10 21:15:47.000000000 +0200
+++ pciutils-3.0.0/lib/access.c	2008-09-01 15:15:27.000000000 +0200
@@ -16,7 +16,8 @@
 void
 pci_scan_bus(struct pci_access *a)
 {
-  a->methods->scan(a);
+  if (a->methods)
+    a->methods->scan(a);
 }
 
 struct pci_dev *