If you are experiencing long delays in tuning in, we have seen the scenario below on Devices and Networks running Sophos End Point protection:

https://secure2.sophos.com/en-us/products/cloud.aspx

It looks like the problem is being introduced by the Sophos End point security application, and specifically the on-access scanning.

Try to disable the Sophos download scanning. This is an option under the Web protection settings.

Here is a discussion of the issue on Sophos forums http://community.sophos.com/t5/Sophos-EndUser-Protection/exception-to-web-control/td-p/3698

To verify this is causing the issue:

(This should only be done temporarily to prove this is causing the issue)

Go to Configure > Anti-virus > Web protection.

See attached screen shot:

The following is  a more permanent adjustment from the Sohpos support site describing how to adjust settings to get around this issue:

http://www.sophos.com/en-us/support/knowledgebase/115656.aspx