No sure exactly what the issue. One possible reason is the proxy in FortiClient. In 3.0, it does not support " TCP Segmentation Offloading" . It may interfere with Lenovo Connection Manager.
You can manually turn off FortiProxy by using some registry hacks. Here is a KC article. http://kc.forticare.com/default.asp?SID=&Lang=1&id=1971. But it' s too old. With 3.0 MR6 or newer, you have to disable a driver called fortishield.
1) Launch a DOS prompt with administrator privileges.
2) Type in " net stop fortishield"
3) Launch regedit and change the registry key described in the KC, and then restart FortiClient.
It may or may not help. If it doesn' t, please file a support ticket.