issues with serial data acquisition

Hi! Recently i was using php-cli with php_dio.dll for manipulate data from and to the serial port (com) under windows xp. Like an adquisition system that inserts data into a mysql database. While i worked with 2 virtual serial ports, my scripts worked fine and efficiently. Knowing that, i tried to test my adquisition data program in a real fisical port (com1 or com2). So far i haven`t any good result with that, nor even making an echo with every char arrived. Nothing is captures by the program. Why this could happen ??? Is there a exception or recommendation working with real data or real ports? Tell me if it is necessary to put the complete script. Regards, Aghor