delete all the entries in the cache and let them be rebuilt.
http://technet2.microsoft.com/WindowsServer/en/Library/cae0e239-267b-45df-88a8-f6f1303830471033.mspx?mfr=trueAlthough, if some asshat on the LAN is running a script to give out fake ARP's then it may happen again.
Let me know how you make out
Widow