Bug 6582 VMPreferencePage - CheckboxTableViewer has no columns anymore
20011204: CheckboxTableViewer has no more columns upon creation. You have to create the first column as well. I encountered the same problem in TemplatePreferencePage, because I used the same code as in VMPreferencePage.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/preferences/TemplatePreferencePage.java
private void selectionChanged1() {		
		IStructuredSelection selection= (IStructuredSelection) fTableViewer.getSelection();
		if (selection.size() == 1) {
			Template template= (Template) selection.getFirstElement();
			fPatternViewer.getTextWidget().setText(template.getPattern());
		} else {		
			fPatternViewer.getTextWidget().setText(""); 
		}
		
		updateButtons();
	}
	
	private void updateButtons() {
		int selectionCount= ((IStructuredSelection) fTableViewer.getSelection()).size();
		int itemCount= fTableViewer.getTable().getItemCount();
		
		fEditButton.setEnabled(selectionCount == 1);
		fExportButton.setEnabled(selectionCount > 0);
		fRemoveButton.setEnabled(selectionCount > 0 && selectionCount <= itemCount);
		fEnableAllButton.setEnabled(itemCount > 0);
		fDisableAllButton.setEnabled(itemCount > 0);
	}
	
	private void add() {
		Template template= new Template();
		template.setContext(TemplateContext.JAVA); 
		EditTemplateDialog dialog= new EditTemplateDialog(getShell(), template, false);
		if (dialog.open() == dialog.OK) {
			fTemplates.add(template);