There are two symptoms to this problem:
Calls are queued, but sit in the queue up to 60 seconds before they connect to an agent in the Ready state. Additionally, the agent that receives the call is in the Reserved state while call is in the queue.
Once the agent ends the call, the agent goes back into the Reserved state and stays in this state for up to 20 seconds before receiving the next call.
Solution
This problem is related to a CRS script issue. This happens because there is a Select Resource step, as shown by C in Figure 1, before the Queued branch. Once the resource is ready to take a call, the resource is flagged as reserved. But, if the Play Prompt step, is not interruptible, then the Select Resource step cannot route the call to the resource until the prompt ends. Therefore if there is a 20 second interruptible prompt the agent remains in the Reserved state for 20 seconds before the call is presented.
This URL should help you:
http://www.cisco.com/en/US/products/sw/custcosw/ps1846/products_tech_note09186a0080262545.shtml