Detaching after fork from child process

Hi,
I have a program in Qt-4.3 and when I run that program, some times it display one error like
"Detaching after fork from child process 6231.". After this message, the program did not work. I have no idea about this error. Please help me to solve this probs

this is too little information for us to be able to say anything about your program.
Specially when it is threaded.
We will need a general description of the threads and how they are supposed to interact, and probably some relevant code.

In order to narrow down the problem, you should do some debugging, so that you will be at least able to say, where and when the error comes, at least on a symptom basis (which with threaded programs not necessarily means its the location of the problem it self - but its a start)