Thank you for the sample kml file. We have inspected it and the problem is related to the fact that it contains coordinates with altitudes. Unfortuntaly altitudes were not supported by the KmlReader in the Q3 release.
This problem will be fixed in the Q3 SP1 but for the time being you can download the hotfix from the "Latest Internal Builds" section in your Client.Net account.
As for sample maps in kml format -- you can check this link here
the Telerik team