We have a redundant CSM 4.1.6 in bridge mode with dual chassis 6509 MSFC3 IOS 12.2(18)SXF7. It has been running fine for the last 8 months when suddenly several of our VIP's stop passing traffic. We can ping the VIP and everything looks operationally normal but, the VIP would not pass traffic to the RIP's. We took a capture and noticed that in the ACK coming from the VIP 172.22.23.101 going to the source it had a bogus ibm mac-address destined for another server. Ultimately we have to reset to fix the problem. Has anyone seen this behavior before? Also we noticed upon failure we get this error in the sh mod csm X tech ft:

Last HB msg Rcvd. at MON OCT 08 23:30:15 2007

Tx at MON OCT 15 20:43:39 2007

Last HB_ACK msg Rcvd. at MON OCT 15 20:43:39 2007

Tx at MON OCT 08 23:30:30 2007