[Serusers] Multiple INVITEs crash Polycom phones

Hello: I have a case where multiple INVITEs crash Polycom phones. I'm wondering if anyone else has seen this and if so how you addressed the problem. We are using SER0.9.7pre3. We have Polycom 550s and Cisco 7960s running SIP 2.2.2.0084 and 7.3 respectively. These phones are configured for simultaneous/parallel ringing which we call a ring group. In a ring group the same 5-digit extension appears on each phone. So in this case the AOR has three contact addresses in the location table. When a call arrives for the AOR all three phones ring and if you answer one of them at least one, possible all, Polycom phones will reboot. Ngrep traces on the proxy show multiple invites being sent to each phone each with a different branch tag in the Via header. I'm not sure what is happening so any insight anyone can share will be appreciated. Polycom admits the reboot is a bug but believes the multiple invites is a configuration problem in our proxy. My questions is where and why does this only cause a problem for Polycom phones? Thanks,steve Senior Network Engineer, Information Systems and Computing Networking and Telecommunications , Suite 221A /6228 University of Pennsylvania Voice:215-573-8396 FAX:215-898-9348