The Political Bureau of the Communist Party of China (CPC) Central Committee has called for great attention to some new problenetms in China's national economy, especially the excessive investment in fixed assets and the shortages of coal, power, oil supplies and transportation facilities.     At a meeting held here Monday on current economic situation chaired by General Secretary Hu Jintao of the CPC Central Committee, the generally-good national economic development was admitted, including satisfying agricultural production, the rise of industrial profits, the robust growth of foreign trade, large amounts of foreign investment, as well as the rapid increase of financial revenue and residents' income.     The investment in some industries grew too fast, however, whichhas led to the rocketing of loans, the meeting pointed out, calling for great attention to these problems and active measures to solve them.     China's economic development is in a crucial stage, the meetingstressed, underscoring the proper control of loan increase, management over land use, strict control of new construction projects and stop of "blind investment" and "low-level repeated construction" in some sectors.