Problems with classicboard Windows 7

I am using a classic board (8ports) and reading in a scale weight all the time. This works fine but when I try to send a command to the scale out the same port it doesnt work properly.If I change the scale to com1 on motherboard works fine please help.

phynamic,

remove the scale and try doing a simple loopback test. Are you sure data is even making it out the serial port?

keith