Active and passive scans as defined in IEEE 802.15.4 are affected by a bug in the CC2420 hardware address recognition causing beacon frames to be rejected. The bug can be avoided in software and is also fixed in the latest hardware revision.
errata for the PCI Express® Base Specification Revision 3.1a Final Release against Base Revision 3.1a. Subsequent errata will be against Base Revision 4.0.