Cisco 7606 CPU Usage Problem

Hi there,
I have a Cisco 7606 with this module on it:

WS-SUP32-GE-3B

and I am using its own 8 port like this:

2 Port Layer two ether-channel uplink to my 4900 Cisco Switch and 1 Layer
two uplink to Internet, and near 10 tunnel to my customers for internet
exchange with BGP peering + some policy map for shaping tunnel interfaces.
My ether-channel traffic on 600Mbps (each port 300Mbps) I get 90% cpu load
and ping time problem on my router, what is the problem??
And when I run: show processs cpu sorted
I get a "Unknown" process eat the cpu process...
I try lots of IOS version but it does not make difference.

My IOS version is:

c7600s3223-adventerprisek9-mz.150-1.S1.bin

and some general configuration:

no ip source-route

!
ip cef load-sharing algorithm original
no ip domain lookup
!
!
!
!
mls ip cef load-sharing full
no mls flow ip
no mls flow ipv6
mls qos
mls cef error action reset
multilink bundle-name authenticated
!
spanning-tree mode pvst
spanning-tree extend system-id
system flowcontrol bus auto
diagnostic bootup level minimal
port-channel load-balance src-ip
username admin secret 5 $1$g6WX$LaQbPyD3qIaHsF5qTqt8g0
!
redundancy
main-cpu
  auto-sync running-config
mode sso
!
!
!
!
vlan internal allocation policy ascending
vlan access-log ratelimit 2000

Thanks

We had some similar issues whenever the BGP scanner process was running.
Ultimately we tracked down the issue to an access list that had the 'log'
statement appended to it, so it was logging all denies. Removing that
cleared up the issue.