java.lang.IllegalStateException: evaluation stack not empty
	at org.zkoss.poi.ss.formula.WorkbookEvaluator.evaluateFormula(WorkbookEvaluator.java:606)
	at org.zkoss.poi.ss.formula.WorkbookEvaluator.evaluateNameFormula(WorkbookEvaluator.java:781)
	at org.zkoss.poi.ss.formula.WorkbookEvaluator.getEvalForPtg(WorkbookEvaluator.java:692)
	at org.zkoss.poi.ss.formula.WorkbookEvaluator.evaluateFormula(WorkbookEvaluator.java:591)
	at org.zkoss.poi.ss.formula.WorkbookEvaluator.evaluateAny(WorkbookEvaluator.java:321)
	at org.zkoss.poi.ss.formula.WorkbookEvaluator.evaluate(WorkbookEvaluator.java:260)
	at org.zkoss.zss.model.impl.sys.formula.FormulaEngineImpl.evaluateFormula(FormulaEngineImpl.java:465)
	at org.zkoss.zss.model.impl.sys.formula.FormulaEngineImpl.evaluate(FormulaEngineImpl.java:347)
	at org.zkoss.zss.model.impl.CellImpl.evalFormula(CellImpl.java:179)
	at org.zkoss.zss.model.impl.CellImpl.getFormulaResultType(CellImpl.java:196)
	at org.zkoss.zss.ui.impl.CellFormatHelper.getRealAlignment(CellFormatHelper.java:417)
	at org.zkoss.zss.ui.impl.CellFormatHelper.getTextCSSStyle(CellFormatHelper.java:438)
	at org.zkoss.zss.ui.impl.CellFormatHelper.getInnerHtmlStyle(CellFormatHelper.java:341)
	at org.zkoss.zss.ui.Spreadsheet$ExtraCtrl.getCellAttr(Spreadsheet.java:3352)
	at org.zkoss.zss.ui.Spreadsheet$ExtraCtrl.getRangeAttrs(Spreadsheet.java:3204)
	at org.zkoss.zss.ui.Spreadsheet.createActiveRange(Spreadsheet.java:1781)
	at org.zkoss.zss.ui.Spreadsheet.renderProperties0(Spreadsheet.java:1741)
	at org.zkoss.zss.ui.Spreadsheet.renderProperties(Spreadsheet.java:1585)
	at org.zkoss.zk.ui.AbstractComponent.redraw(AbstractComponent.java:1810)
	at org.zkoss.zk.ui.AbstractComponent.redrawChildren(AbstractComponent.java:1887)
	at org.zkoss.zk.ui.AbstractComponent.redraw(AbstractComponent.java:1829)
	at org.zkoss.zk.ui.sys.HtmlPageRenders.outPageContent(HtmlPageRenders.java:629)
	at org.zkoss.zul.impl.PageRenderer.renderDesktop(PageRenderer.java:104)
	at org.zkoss.zul.impl.PageRenderer.render(PageRenderer.java:56)
	at org.zkoss.zk.ui.impl.PageImpl.redraw(PageImpl.java:874)
	at org.zkoss.zk.ui.impl.UiEngineImpl.execNewPage0(UiEngineImpl.java:538)
	at org.zkoss.zk.ui.impl.UiEngineImpl.execNewPage(UiEngineImpl.java:356)
	at org.zkoss.zk.ui.http.DHtmlLayoutServlet.process(DHtmlLayoutServlet.java:217)
	at org.zkoss.zk.ui.http.DHtmlLayoutServlet.doGet(DHtmlLayoutServlet.java:136)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:707)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
	at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511)
	at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:401)
	at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
	at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
	at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:766)
	at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:450)
	at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
	at org.mortbay.jetty.Server.handle(Server.java:326)
	at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
	at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:928)
	at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:549)
	at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:212)
	at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
	at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:410)
	at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582)