Hmm, well when I try this at http://demo.silverstripe.com, I get a different error at a seemingly different place. I'll paste it here for Andrew to check over for the 2.1 release:
Error in Ajax evaluator on line 973: illegal character var newNode = $('sitetree').createTreeNode(17, \"\", \"SiteTree\"); var parentNode = $('sitetree').getTreeNodeByIdx(0); if(parentNode) parentNode.appendTreeNode(newNode); " ( ? "newNode.selectTreeNode(); " : "") ; $('sitetree').setNodeTitle("15", ""); $('Form_EditForm').getPageFromServer(15); $('Form_EditForm').loadActionsFromString(' '); $('Form_EditForm').updateStatus('Saved (new)'); statusMessage('Saved. Status changed to \'Saved (new)\'', 'good');