I've seen this on my Windows 7 computer, and searches have turned up others in Vista/7 who have seen the same. However, I've not yet found (or perhaps have just missed) a good explanation for this.
These two addresses are static in my ARP table, but I don't know for what purpose:
126.96.36.199 01-00-5e-00-00-16 static 188.8.131.52 01-00-5e-00-00-fc static
One website calls these MAC addresses "Internet Reserved by IANA"/"Internet Multicast"/"MPLS Multicast". Still, I don't understand the purpose of these addresses in my table, since they wouldn't match anything on the local subnet.