Ok, so the update notes on SP4 say it fixes a problem I was having with SP3.. specifically: Fixed: * Bug when call is parked and un-parked multiple times on same or different parking slots This problem is still evident in SP4. When I pickup a call parked on SP0, I can not re-park that call on SP0. I can re-park it on any other shared parking slot fine, just not the shared parking slot from which the call was picked up. I have tested this thoroughly with Cisco SPA509G and Cisco SPA504G phones. I have used the xfer method, bxfer method and also just tapping the shared park line key I have configured. All 3 ways exhibit the exact same symptoms. When a call is attempted to be re-parked on the same shared park from which it was picked up, the shared park becomes active, but the actual line never releases and is placed on hold instead of going into the shared park.