Hi Kevin,
This issue is more related to the positioning of the splitter itself. Notice that the splitter is moving as well along with the resize of the window. Having the sliding pane positioned absolutely, it stays in place, but the splitter starts moving. A solution to this is to cause the sliding pane to collapse when the window start resizing. Please, try the following method as an event handler to the OnClientLoaded client-side event of the splitter:
Just make sure that the getSlidingZones method returns the correct sliding zone as per your application.
Thank you for reporting this issue in our demos. As a sign of gratitude for your efforts I have updated your Telerik points.
Kind regards,
Niko
the Telerik team
Check out
Telerik Trainer, the state of the art learning tool for Telerik products.