Looks like you are missing part of the url TeamPulse needs to connect to TFS 2010. It needs to be shown which project collection it is connecting to. Your URL should look like this:
Please give that a try and let us know if it resolves your issue.
the Telerik team
Do you want to have your say when we set our development plans? Do you want to know when a feature you care about is added or when a bug fixed? Explore the Telerik Public Issue Tracking
system and vote to affect the priority of the items.