No MO calls on CS while PS services are all up

[foufou007]

Colleagues,

I have an issue originating CS calls on a new site 2g/3G Huawei while all PS service are fine. The message I am getting is IU release due to UE generated signaling release code 40.
On 3G the error code is "Radio resource unavailable"
On 2G the error code is "error in codec negotiation"

Appreciate your thoughts.

[punto]

On which technology UE was when call started,
on which technology was UE before bad event and
how is set up priority of layers , is it to use 3G where possible and to have 2G as safety layer ?