Generally, you should define RadTabStrip as an AJAX initiator with the updated controls being the RadMultiPage and the RadTabStrip itself. RadTabStrip should have AutoPostBack set to "true".
The above setup will ensure consistent tab and pageview switching. However, if you need to add or remove tabs and pageviews based on another control on the page, you can defined that control as an initiator, with the RadTabStrip and the RadMultiPage being updated controls.
the Telerik team