We had such problems in previous versions of the splitter, when you place the map control in a sliding pane. This problem is fixed in the latest version of the Telerik.Web.UI assembly. However, the problem was fixed only for the case when the page is not in quirks mode. That is why, please make sure that:
In case the above suggestions do not help you, please post the code of your test page that demonstrates the problem here.
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