Thank you for contacting us. Currently it is not possible to adjust the size of the drop zones.However, I'll add your feature suggestion in our public issue tracking system
under the name "TreeView: Allow adjusting the size of the drop zones"
and it will be available for tracking and voting tomorrow the latest. If this feature request gathers enough popularity we will definitely implement it.
On a side note, I'd like to inform you that we've just released an online tool that allows you to reduce the size of your Silverlight applications. For more information, please visit http://blogs.telerik.com/blogs/posts/10-06-10/telerik_assembly_minifier.aspx
the Telerik team
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Telerik Public Issue Tracking
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