qextersial communication problem

Hi everyone,

I made an application that sends and receives data with qextserial over a com port.
Now I tried to change my development computer.
Developing under Windows *duck*

But if I now communicate with qextserial it does no longer work.
I tried compiling the qespta example of qextserial 1.1 and the program thinks it opens ports and closes them. On the bridge to the modul i try to communicate with theer is an led which shows if the port is opend from the pc or not.

with the example and my program this led is on when port is open, but it is not very bright.
When i communicate with the modul with a scripting program the led is very bright.

Both my program and the scripting program have tried to send something over the serialport. My sniffer that overlooks the communication sees the exact same output from my pc, but the input changes depending if i send with qextserialport or not.

Any ideas what the problem could be?