CentOS - Sep 2005 - snmp interface values on x86_64?

I'm trying to graph the interface traffic from centos 3.5 x86_64
boxes using snmp and cacti (running on an x86 box).  Everything starts
out OK after a reboot, but it looks like after the total traffic out
passes 2^32 bytes the values returned in snmp 5-minute rates go crazy.
Is this a known bug, and if not, where should it be reported?

-- 
  Les Mikesell
   lesmikesell at gmail.com