Linksys SPA8000 Annoying Buzz/high pitch tone during first 1-2 seconds of conversation

Hi All,

I need some help.

Currently running FreePBX 3 with a Linksys SPA8000. When a call initiated either externally or internally rings the analogue telephone connected to the Linksys SPA8000 for the first 1-2 seconds there is an annoying high pitch tone/buzz.

Has anyone come across this problem ?

I have made changes to input/output gains on Linksys SPA8000 unit, but to no avail.