I should clarify what I said about QoS in the post above:
1)I was referring to being logged into the IPSI. "show qos" will display:
Call Control 802.1p: 6
Call Control Diffserv: 46
Enable VLan tag: off
VLan tagging is at Layer 2, and if you enable it in the IPSI the switches must also be set up for VLan tagging.
2)The QoS setting in "change ips 1" screen from ASA refers to layer 3, and defines if QoS is being used in the control link from the S8700 to the IPSI. If it is turned on from this screen, it must also be turned on in "Configure Server" from the Web Interface. But, we've also had problems when doing this, as you have, and the general thinking has been that enabling QoS from the server also enables VLAN tagging from the server, which won't work if vlan tagging is off on both the IPSI and the switches in the middle. I haven't tested this, but maybe someone else out there has.....
Anyhow, I think it basically comes down to always leaving it off..........