I installed a SPA9000, 1 SPA400, 4 SPA942 phones and 5 SPA901 phones using the latest wizard and updating all firmware as I went. The SPA400 is contected to 1 PSTN line on FXO=1. The 4 SPA942 phones use the SPA400 for a total of 4 voicemail boxes. Line 1 on the SPA9000 is connected to voip.ms and registers fine. Line 2 is connected to SPA400 for the gateway to the PSTN line. Innitially the system worked for a week before inbound and outbound calls (both lines) would cut out the audio every 4-10 seconds and reconnect again. (Repeating this annoying cycle continuously for the duration of the call.) We have changed the Switch to a SLM240p and set all settings as per the SPA9000 setup manual. I have set the router yesterday to reserve all the SPA phone ip's. The SPA9000 as well as the SPA400 and switch all have static ip addresses. The status on the SPA9000 shows all the phones as expected. I have a very unhappy customer. I would appreciate any help. I have an active file with Cisco engineers who are trying to help me sort this out.