Hello Stephen Lam,
You can reproduce the same result with a simple IFRAME element:
That is why, I suppose that the script, which is executed when the page (http://mail.live.com/) loads, checks whether the page is opened in an IFRAME and in case it is, redirects the whole page. As the code is part of the http://mail.live.com/ page, the pane (splitter) cannot prevent it from executing.
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?
Telerik Public Issue Tracking
system and vote to affect the priority of the items.