Speaking of this again, I really think it's an IOS bug and not a "your router's out of gas" issue.

Last week we had another router running 12.2S code (12.2(14)S3 on a 7206vxr NPE300) start doing this, only it was several thousand ignores/s on the IO/FE built-in port. That port typically did <10mbit/s and was not doing any unusual mbps or pps at the time. CPU load on that router is typically 10-20%. We tried bouncing the interface, bouncing the switch port it connected to, replacing the patch cable, actually rebooting that switch, nothing made a difference. I wanted to reboot the router, as I assumed that would clear it up, but that would have been several more minutes of unacceptable downtime in the middle of the day.

We'd planned for some time to remove the traffic from that router, so we just moved that up and "replaced it" with a layer 3 3550 switch port. The 3550 had no issues with being the uplink for the switch we moved off of the 7206's f0/0.