I have observed the same thing with new Sony and HP notebooks. One of our micros has LEDs on TxD and RxD. You can see them switch when you open the port by running a terminal program.

Some older DOS terminal programs won't properly open the port. The Micro will then transmit OK, but it will not receive. However, if you open a DOS window, then run a terminal program that properly opens the COM port, you can then use the other COM port program in that DOS window.

I think I remember that booting to Safe Mode makes this problem go away. If it is related to power management, would this be disabled in Safe Mode?


- Tom Bachmann