I would first of all check with a newer client, v11.20 SR5 is out on the market. You may find the releases at http://download.qlik.com . It should work fine to only update the Desktop client.
I am assuming you are leasing a license and want to connect via QV Desktop to the server, is this correct?
Do you have some screenshots?
The product should not hang at any time though, and this might be a bug. You might want to consider filing a support case for a thorough investigation.