Hi.In our case the reason was the operator. He was using a semi-blind transfers.Take a look to this BUG:Calls gets stuck in queue when two or more actions are done to a call at the same timehttps://bst.cloudapps.cisco.com/bugsearch/bug/CSCve26225 Sy...
Hi Richard.
The conclusion of the TAC was:
Is not an issue. Is the way that it works.(Haw they handle the CTI ports)
As Operator you must decide if you want a blind transfer or consult transfer and keep it in that way. I meant: To blind transfer : "...