In a runat=server script in a onserverload callback, asking for: node.ownerDocument.defaultView.getComputedStyle(node, null); returns null, but the expected behavior is to receive an object of style properties. The attached file demonstrates the bug. You can uncomment out the commented lines to see how it would work in a browser (Firefox) instead of a runat=server section. This bug currently prevents the Dojo Toolkit from working in Aptana: http://www.dojotoolkit.org/forum/dojo-core-dojo-0-9/dojo-core-support/running-dojo-1-2-aptana-jaxer