Javascript program is not cached on Symbian like other platforms

#if !defined(Q_OS_SYMBIAN) //XXX Why doesn't this work?
        if (!dd->cachedPrograms.at(progIdx)) {
            dd->cachedPrograms[progIdx] = new QScriptProgram(expression, url, line);
        }

        expressionFunction = evalInObjectScope(ctxt, me, *dd->cachedPrograms.at(progIdx), 
                                                     &expressionContext);
#else
        expressionFunction = evalInObjectScope(ctxt, me, expression, &expressionContext);
#endif