I understand that you want to know how to get 60 minutes of pause time with the Live Buffer feature.
You need to run the connection to your Slingbox for at least 60 minutes. This way, you will be able to pause the SlingPlayer for 60 minutes. This information is included on the following link:
On the other hand, if you are using the web-based application through www.slingbox.com, you must know that this feature works for 30 minutes. The following link will allow you to get further details:
Hope this helps.