why does qt program meet segmentation fault?

My qt program has nothing to do with the serial port, and do not have to open the serial port. But, when I was trying to lauch it under the Linux system (my qt version is qtopia4.1.2), why did it show segmentation fault of my qt program when I use the serial port to transit some data into the computer which was lauched the qt program ? I know there must be somebody here met this problem before, and solved it properly, hope you can give me some advice. Many thanks!!

Run your application under a debugger and see where it crashes.